Desiccant, organic thin film including same, organic layered film in which organic thin film is layered, and electronic device provided therewith

ABSTRACT

The present invention addresses the problem of providing a desiccant that can be used for passivation of an electronic device such as an organic electroluminescence element against moisture permeation, as well as an organic thin film including the desiccant, an organic layered film in which the organic thin film is layered, and an electronic device that is provided therewith. This desiccant is characterized by including a compound that emits a hydrophobic substance by absorbing water. This organic thin film is characterized by including this desiccant.

TECHNICAL FIELD

The present invention relates to a desiccant, an organic thin filmcontaining the same, an organic laminated film in which the organic thinfilms are laminated, and an electronic device having the same. Morespecifically, the present invention relates to a desiccant that may beused for sealing moisture permeation to an electronic device such as anorganic electroluminescence element, and an organic thin film containingthe desiccant.

BACKGROUND

In the industry, a number of electronic components, includingtransistors and diodes, are subjected to a process called sealing(passivation) to avoid the degradation caused by water and oxygen. Inparticular, organic thin film transistors, organic thin film solarcells, and organic electroluminescence elements (hereinafter referred toas organic EL elements), in which electron conduction is performed byorganic compounds, are particularly sensitive to water molecules, andextremely high sealing is required. Among them, since the organic ELelement is in an excited state having the highest reactivity as anorganic matter during light emission, the number of water moleculesrather than the water concentration must be dealt with, and a desiccantagent for capturing water molecules is required in addition to a highgas barrier. In addition, it is necessary to adhere a film or glasshaving a gas barrier property to a device substrate, and it is necessaryto take measures against permeation of water or oxygen through theadhesive from the adhered portion, and in this sense, the role of adesiccant is also important.

In view of the technical background described above, in the sealingmethod, there are known: (1) a solid sealing film made of a denseinorganic oxide or inorganic nitride; (2) a desiccant of a physicalabsorption type such as zeolite or porous silica gel; and (3) adesiccant of a chemically reactive type which removes water molecules byimmediately chemically reacting with water molecules such as alkalineearth metal oxides or metal hydrides.

The manufacturing method (1) is characterized in that it is manufacturedby vacuum deposition typified by vapor deposition, sputtering, CVD(Chemical Vapor Deposition), and ALD (Atomic Layer Deposition), and isexcellent in water vapor barrier property because a plurality of densefilms can be formed, but on the other hand, the manufacturing methodrequires a large-sized device and is unsuitable for continuousproduction such as roll-to-roll, so that the manufacturing cost is highand the problem is large for mass and inexpensive production.

On the other hand, the method for removing the water molecules of (2)and (3) can be selectively used depending on the allowable moistureconcentration of the device, but in general, the desorption phenomenonof water molecules cannot be avoided if the adsorption mechanism is thechemical equilibrium between water and adsorbent, such as silica gel,zeolite, montmorillonite of (2), and the method cannot be applied toorganic thin film solar cells or organic EL elements that require a highdegree of water molecule removal.

The method (3) typified by barium oxide, or strontium oxide hasexcellent ability as a desiccant because it has high reactivity withwater molecules, but has many problems such as immediate reaction withwater at atmospheric pressure, deterioration in performance, and theattendant risk of heat generation, and the effect is temporary andunsuitable for long-term storage because only stoichiometric amounts ofwater can be captured in the device.

As an example of a chemical reaction type desiccant, a desiccant usingwater absorption by hydrolysis has been proposed (for example, seePatent Document 1). However, the disclosed alumina ring trimer still hasa low water vapor barrier property for application to a sealing film ofan electronic device.

PRIOR ART DOCUMENTS Patent Document

Patent Document 1: JP-A No. 2005-000792

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

The present invention has been made in view of the above problems andcircumstances, and an object of the present invention is to provide adesiccant that may be used for sealing moisture permeation to anelectronic device such as an organic electroluminescence element, anorganic thin film containing the same, an organic laminated film inwhich the organic thin films are laminated, and an electronic deviceincluding the same.

Means to Solve the Problems

In order to solve the above-mentioned problems, the present inventor hasfound a new desiccant which is a chemical reaction type desiccant andwhich can release a hydrophobic substance which prevents thetransmission of moisture by the amount of reaction, and has found thatby containing the desiccant, an organic thin film functioning as asealing film against moisture permeation for an electronic device suchas an organic electroluminescent element can be obtained, and has led tothe present invention.

That is, the present inventors have tried to create a technique capableof realizing the following phenomena in order to overcome theabove-mentioned problems.

(I) To be provided with a drying property (desiccant property) thatreacts with water molecules.(II) To release a substance that has a property of repelling water as afunction of its reaction with water.(III) To be capable of forming a coating film under atmosphericpressure.

If materials and technologies can be constructed that combine thesethree elements, the penetration of water molecules may be effectivelyprevented in the heart of the electronic device, water-repellentmaterials may be produced in accordance with the amount of water thathas penetrated, thereby preventing the penetration of water vapor undera new technical idea completely different from conventional water vaporbarrier properties, and if coating can be performed under atmosphericpressure, sealing may be made inexpensively and over a large area, andit is considered that there is a possibility that a hidden problem(i.e., inexpensive and effective sealing) that actually became abottleneck in manufacturing cost toward the IoT age coming from now onmay be solved at once.

That is, the above-mentioned problem according to the present inventionis solved by the following means.

1. A desiccant comprising a compound which releases a hydrophobicsubstance upon absorption of water.2. An organic thin film containing the desiccant described in Item 1.3. The organic thin film described in Item 2, wherein the desiccantcontains an organometallic oxide.4. The organic thin film described in Item 3, wherein the organometallicoxide has a structure represented by the following Formula (1),

R-[M(OR₁)_(y)(O—)_(x-y)],n-R   Formula (1):

(In Formula, R represents a hydrogen atom, an alkyl group having one ormore carbon atoms, an alkenyl group, an aryl group, a cycloalkyl group,an acyl group, an alkoxy group, or a heterocyclic group, provided that Rmay be a carbon chain containing a fluorine atom as a substituent, Mrepresents a metal atom, OR₁ represents an alkoxy fluoride group, xrepresents a metal valence, y represents any integer between 1 and x,and n represents a degree of polycondensation, respectively.)

5. The organic thin film described in Item 2, wherein the fluorine ratioof the organic thin film satisfies the following Expression (a),

0.05≤F/(C+F)≤1,   Expression (a):

(in Expression (a), F and C represent densities of fluorine atoms andcarbon atoms, respectively.)

6. The organic thin film described in Item 4 or Item 5, wherein themetal atom represented by M is a Group 2 element.7. The organic thin film described in Item 6, wherein the metal atomrepresented by M is strontium.8. The organic thin film described in any one of Items 4 to 7, whereinthe organic thin film contains at least two types of organometallicoxides having a structure represented by Formula (1) and wherein atleast one type of metal atom is a Group 2 element.9. An organic laminated film in which the organic thin film described inany one of claims 2 to 8 and another organic thin film are laminatedadjacently.10. An electronic device comprising: at least an organic functionallayer; and an organic thin film described in any one of Items 2 to 8 oran organic laminated film described in Item 9 above the organicfunctional layer.11. The electronic device described in Item 10, wherein the organic thinfilm is an elution preventing film, and is disposed between the organicfunctional layer and the organic thin film.12. The electronic device described in Item 10 or 11, wherein theelectronic device is an organic electroluminescence element.

Effects of the Invention

By the above-mentioned means of the present invention, it is possible toprovide a desiccant that is used for sealing moisture permeation to anelectronic device such as an organic EL element, an organic thin filmcontaining the same, an organic laminated film in which the organic thinfilm is laminated, and an electronic device including the same.

The expression mechanism or action mechanism of the effect of thepresent invention is not clarified, but is inferred as follows.

The desiccant of the present invention and the organic thin filmcontaining the desiccant function as a chemical reaction type getteragent. Further, it is a new desiccant and a sealing film for preventingpermeation of water, which releases a hydrophobic substance by an amountcorresponding to the reaction with water (moisture). Specifically, theorganometallic oxide having the structure represented by Formula (1)described later is hydrolyzed to produce an equal mole of fluorinatedalcohol with quenched water molecules, which has a water repellentfunction, thereby preventing further penetration of water. Therefore, itis an innovative technology that has a characteristic not found inconventional desiccants and organic thin films, in which the effect ofpreventing the penetration of moisture is extremely high than that ofconventional desiccant-type desiccants. That is, in addition to thedrying property (desiccant property) of the single composition film, thewater-repellent function is added by the reaction with moisture toexhibit a synergistic effect (synergy effect). This is an innovativetechnology with features not found in conventional desiccants andorganic thin films.

The organic thin film containing the desiccant of the present inventionmay be formed, for example, by using a metal alkoxide solution as a rawmaterial, and synthesizing an organic-inorganic hybrid compound byhydrolysis of a metal alkoxide and a subsequent polycondensationreaction, which is generally called a sol-gel method.

In addition to sealing, a sol-gel method is widely known as aconventional means for forming a film of an inorganic oxide by a coatingmethod. In this method, generally, a metal alkoxide solution is used asa raw material, and an inorganic oxide is formed by hydrolysis of themetal alkoxide followed by a polycondensation reaction, and when a partof the metal alkoxide is not an alkoxy group but an alkyl group or anaryl group, the group is retained even after the sol-gel reaction, sothat an organic-inorganic hybrid compound film based on the inorganicoxide may be formed.

Basically, all metal elements which can be alkoxylated may be applied tothis sol-gel method, but in practice, gelation occurs when the solutionis made in the air, and most of the cases cannot be applied, and onlysilicon (tetraalkoxysilane) is practically used. The reason for this isthat, when the metal element is titanium or zirconium, the alkoxidecompound itself is Lewis acid, which catalytically accelerates thedehydration polycondensation reaction after the hydrolysis reaction, andgelation occurs immediately. Further, in the case of alkali metal oralkaline earth metal, since alkoxide is basic, the first hydrolysisreaction is very fast, while the dehydration polycondensation reactionis slow, so that it is difficult to obtain an organometallic oxide.Since silicon alkoxide has intermediate properties, it is only suitablefor the synthesis of organic oxides or the formation of organometallicoxide thin films by the sol-gel method.

On the other hand, when the metal alkoxide is dissolved in an excess ofalcohol (A), the metal alkoxide is replaced with (A) from the chemicalequilibrium to form the metal (A) alkoxide. At this time, when (A) is analcohol substituted with a fluorine atom, the resulting metalfluorinated alkyloxy compound (hereinafter referred to as “metalfluorinated alkoxide”) can moderate the sol-gel reaction rate. This isbecause, although the electron density on the metal element is loweredby the electron attraction effect of the fluorine atom and thenucleophilic reaction of the water molecule is accelerated, the effectof elimination of water by the fluorine atom is larger than thisacceleration by the fluorine atom, and the water molecule does notapproach the metal element. Consequently, the so-called frequency factoris greatly lowered, and as a result, the hydrolysis rate is slowed, andan acid catalytic effect is exhibited because an alkoxide compound of,for example, titanium, zirconium, or a transition metal having an emptyd orbital (for example, tetravalent vanadium or tetravalent tungsten) isa Lewis acid, and an organometallic oxide having a high molecular weightis apt to be generated because the dehydrogenation condensation reactionor dealcohol polycondensation reaction is accelerated.

This effect makes it possible to satisfy all of the above-mentioned (I)to (III). In particular, with respect to (II), even if the usual metalalkoxide could not be handled substantially due to the progress ofgelation, but it becomes possible to handle in the presence of thefluorinated alcohol. And by applying high energy such as ultravioletlight, plasma irradiation, or microwave irradiation to the resultingfilm, a high density organic metal oxide film is formed continuouslyfrom the surface of the thin film. As a result, the thin film has adrying property (desiccant property) of (I), and further, sinceunreacted metallized alkoxide remains inside, it exhibits the effect of

(II) because it reacts with incoming water to form fluorinated alcohol.Therefore, it becomes possible to form a new thin film having theeffects of (I) and (II) together.

Further, metal alkoxides substituted with fluorinated alcohols can alsoeffectively suppress the reaction and salt formation between differentmetal alkoxides because the frequency factor is reduced due to theelimination effect of fluorine atoms. Alternatively, a plurality ofmetal alkoxides can coexist in a solution as a metal fluoride alkoxide,and a thin film obtained from the solution can give a mixed inorganicoxide thin film. This may be said as one of the present invention.

For example, titanium tetraisopropoxide and barium dibutoxide, whichusually form Lewis acid/Lewis base pairs and to form gel, do not formgel even when they are diluted in a large excess of tetrafluoropropanol(TFPO) and then mixed, but can be applied as they are to form a thinfilm by the sol-gel method, and a mixed organometallic oxide film may beformed by applying high-energy such as ultraviolet rays to the thinfilm.

That is, the present invention is not limited to a desiccant that simplyproduces a water-repellent compound, but a plurality of metal alkoxideswhich have conventionally been difficult to coexist are stably present,and the resulting mixed organometallic oxide thin film itself falls intothe category of the present invention. This is a technique which has notbeen realized in practice, although it is likely to be realized in thepast, and the realization of this technology is expected to exert afunction which has not been achieved so far in various applicationareas, and the positive influence of the present invention on theindustry is great.

Therefore, the present invention is to be distinguished from the similarprior art because the thin film formation by the sol-gel method usingthe conventional metal alkoxide is different in concept, the function ofthe formed thin film is different, and furthermore, a mixtureorganometallic oxide thin film, which has not been possible heretofore,is realized.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross-sectional view indicating an example of aconfiguration of an organic EL element which is an electronic device ofthe present invention;

FIG. 2 is a cross-sectional view indicating a solar cell composed of anorganic photoelectric conversion element of a bulk heterojunction type;

FIG. 3 is a cross-sectional view indicating a solar cell composed of anorganic photoelectric conversion element having a tandem bulkheterojunction layer;

FIG. 4A is a diagram indicating an exemplary configuration of an organicthin film transistor;

FIG. 4B is a diagram indicating another exemplary configuration of theorganic thin film transistor;

FIG. 4C is a diagram indicating another exemplary configuration of theorganic thin film transistor;

FIG. 4D is a diagram indicating another exemplary configuration of theorganic thin film transistor;

FIG. 4E is a diagram indicating another exemplary configuration of theorganic thin film transistor;

FIG. 4F is a diagram indicating another exemplary configuration of theorganic thin film transistor;

FIG. 5 is a cross-sectional view of an organic EL element used in theembodiment;

FIG. 6 is a cross-sectional view of an organic EL element used in theembodiment;

FIG. 7 is a cross-sectional view of an organic EL element used in theembodiment;

FIG. 8 is a cross-sectional view of an organic EL element used in theembodiment;

FIG. 9 is a cross-sectional view of an organic EL element used in theembodiment.

EMBODIMENTS TO CARRY OUT THE INVENTION

The desiccant of the present invention is characterized in that itcontains a compound which releases a hydrophobic substance by absorbingwater. This feature is a technical feature common to or corresponding toeach embodiment.

The organic thin film of the present invention is characterized in thatit contains the desiccant. The organic thin film functions as a thinfilm having a high sealing property against moisture permeation withrespect to an electronic device.

In an embodiment of the present invention, from the viewpoint ofexpressing the effect of the present invention, it is preferable thatthe desiccant contained in the organic thin film contains anorganometallic oxide, and the organometallic oxide preferably has astructure represented by Formula (1). A thin film having a high sealingproperty against moisture permeation can be formed by the compoundhaving the structure represented by Formula (1).

Further, it is preferable that the fluorine ratio of the organic thinfilm of the present invention satisfies the above Expression (a), and byincreasing the fluorine ratio, it is possible to provide a thin filmhaving a higher sealing property against moisture permeation withrespect to an electronic device.

In Formula (1), it is preferable that the metal atom represented by M isselected from Ti, Zr, Sn, Ta, Fe, Zn, Si, and Al from the viewpoint offurther enhancing the effect of the present invention.

Further, it is preferable that the metal atom represented by M is aGroup 2 element from the viewpoint of further enhancing the effect ofthe present invention.

In addition, it is preferable that the metal atom represented by M isstrontium from the viewpoint of further enhancing the effect of thepresent invention. Further, it is preferable that at least two kinds oforganic metal oxides having different metal atom types and having thestructure represented by Formula (1) are contained, and at least onekind of metal atom is a Group 2 element.

The method for producing an organometallic oxide according to thepresent invention is characterized in obtaining the effect of thepresent invention by using a mixed solution of a metal alkoxide or ametal carboxylate and a fluorinated alcohol.

Further, as a method for manufacturing an organic thin film of thepresent invention, it is preferable to have a step of manufacturing theorganic thin film by a coating method or an inkjet printing method.Further, it is preferable to have a step of irradiating the organic thinfilm with vacuum ultraviolet light from the viewpoint of efficientlyproducing a dense and uniform organic thin film.

Further, it is preferable that the organic thin film of the presentinvention is provided in the electronic device as an organic laminatedfilm in which another organic thin film is laminated, and when theorganic thin film absorbs moisture and releases a hydrophobic compound,the influence of penetration of the compound into the electronic devicemay be alleviated by the other organic thin film. Therefore, it ispreferable that the other organic thin film is an elution preventingfilm.

The organic thin film or the organic multilayer film of the presentinvention is provided in an electronic device, and it is preferable thatthe electronic device is an organic electroluminescent element, a solarcell using an organic photoelectric conversion element, or an organicthin film transistor from the viewpoint of providing an electronicdevice in which transmission of moisture from the outside is preventedand performance degradation of the device is suppressed.

Hereinafter, detailed descriptions will be given of the presentinvention, its constituent elements, and modes and modes for carryingout the present invention. In the present application, “to” is used inthe meaning that numerical values described before and after areincluded as a lower limit value and an upper limit value.

[1] Desiccant

The desiccant of the present invention is characterized in that itcontains a compound which releases a hydrophobic substance by absorbingwater.

The desiccant of the present invention is an alcohol-substitutedorganometallic oxide or a polycondensate of an organometallic oxideobtained by subjecting a metal alkoxide to alcoholysis in the presenceof an excess of alcohol. In this case, by using a long-chain alcohol inwhich a fluorine atom is substituted in the β position of the hydroxygroup, an organometallic oxide containing a fluorinated alkoxide isobtained, which is a desiccant of the present invention.

On the other hand, the organometallic oxide is sintered or irradiatedwith ultraviolet rays to accelerate a sol-gel reaction and form apolycondensate. In this case, when a long-chain alcohol in which afluorine atom is substituted in the β position of the hydroxy group isused, the hydrolysis rate is decreased by decreasing the frequencyfactor of moisture existing around the metal in the metal alkoxide dueto the water repellent effect of fluorine, and this phenomenon is usedto suppress a three-dimensional polymerization reaction, and a uniformand dense organic thin film containing a desired organometallic oxidewill be formed.

The organometallic oxide contained in the desiccant of the presentinvention is shown in the following Reaction Scheme I. In the structuralformula of the polycondensate of the organometallic oxide aftersintering, “M” in the “O-M” part further has a substituent, but isomitted.

The organic thin film formed by polycondensation of the above-mentionedorganometallic oxide by sintering or UV radiation is hydrolyzed bymoisture (H₂O) from the outside of the system according to the followingReaction Scheme II, and a fluorinated alcohol (R′—OH) which ishydrophobic materials is released. The fluorinated alcohol furtherpassivates moisture from penetrating into the interior of the electronicdevice.

That is, the desiccant of the present invention has a characteristicthat the fluoride alcohol produced by hydrolysis exhibits a synergisticeffect (synergistic effect) on the sealing property by adding a waterrepellent function by reaction with moisture in addition to the originaldrying property (desiccant property) because of water repellency.

In the following structural formula, “M” of “O-M” part further has asubstituent, but is omitted.

The desiccant of the present invention preferably contains anorganometallic oxide having a structure represented by the followingFormula (1) as a main component. The “main component” means that 70% bymass or more of the total mass of the desiccant is preferably theorganometallic oxide that releases a hydrophobic substance, morepreferably 80% by mass or more, and particularly preferably 90% by massor more.

R-[M(OR₁)_(y)(O—)_(x-y)],n-R   Formula (1):

(In Formula, R represents hydrogen atoms, an alkyl group having 1 ormore carbon atoms, an alkenyl group, an aryl group, a cycloalkyl group,an acyl group, an alkoxy group, or a heterocyclic group, provided that Rmay be a carbon chain containing a fluorine atom as a substituent, Mrepresents a metal atom, OR, represents a fluorinated alkoxy group, xrepresents a metal valence, y represents any integer between 1 and x,and n represents a degree of polycondensation, respectively). Further,it is preferable that the fluorine ratio in the organic thin film of thepresent invention satisfies the following Expression (a).

0.05≤F/(C+F)≤1,   Expression (a):

The measurement meaning of Expression (a) is to quantify that an organicthin film produced by the sol-gel method requires a certain amount ormore of fluorine atoms. F and C in the above Expression (a) representthe densities of fluorine atoms and carbon atoms, respectively.

A preferable range of Expression (a) is:

0.2≤F/(C+F)≤0.6.

The fluorine ratio may be obtained by coating a sol-gel solution usedfor forming an organic thin film on a silicon wafer to produce a thinfilm, and then analyzing the thin film with an element by SEM-EDS(Energy Dispersive X-ray Spectoroscopy: Energy-dispersive X-rayanalyzer) to obtain the densities of fluorine atoms and carbon atoms,respectively. As an example of the SEM/EDS device, JSM-IT100(manufactured by Nippon Electronics Co., Ltd.) may be cited.

The SEM/EDS analysis is characterized by high-speed, high-sensitivity,and high-precision detection of elements.

The organic metal oxide according to the present invention is notparticularly limited as long as it is produced by the sol-gel method,and for example, a metal oxide containing one or more metals selectedfrom metals introduced in “Science of Sol-Gel Method” P13, P20, lithium,sodium, copper, calcium, strontium, barium, zinc, boron, aluminum,gallium, yttrium, silicon, germanium, lead, phosphorus, antimony,vanadium, tantalum, tungsten, lanthanum, neodymium, titanium, andzirconium may be cited as an example. Preferably, the metal atomrepresented by M is selected from titanium (Ti), zirconium (Zr), tin(Sn), tantalum (Ta), iron (Fe), zinc (Zn), silicon nitride (Si), andaluminum (Al), from the viewpoint of obtaining the effect of the presentinvention.

Further, it is preferable that the metal atom represented by M is aGroup 2 element, and among them, magnesium (Mg), strontium (Sr), andbarium (Ba) are more preferable, and strontium (Sr) is particularlypreferable. The organic thin film of the present invention is alsodescribed.

It is preferable from the viewpoint of obtaining the effect of thepresent invention that at least two kinds of organometallic oxideshaving the structure represented by Formula (1) are contained, and atleast one kind of metal atom is a Group 2 element.

In the above Formula (1), OR, represents a fluorinated alkoxy group.

R₁ represents an alkyl group, an aryl group, a cycloalkyl group, an acylgroup, an alkoxy group, or a heterocyclic group substituted with atleast one fluorine atom. Specific examples of each substituent will bedescribed later.

R represents a hydrogen atom, an alkyl group having one or more carbonatoms, an alkenyl group, an aryl group, a cycloalkyl group, an acylgroup, an alkoxy group, or a heterocyclic group. Alternatively, at leasta part of the hydrogen of each group may be substituted with halogen. Itmay also be a polymer.

The alkyl group may be substituted or unsubstituted, and specificexamples include: a methyl group, an ethyl group, a propyl group, abutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, ahexyl group, a heptyl group, an octyl group, a nonyl group, a decylgroup, an undecyl group, a dodecyl group, a tridecyl group, a tetradecylgroup, a pentadecyl group, a hexadecyl group, a heptadecyl group, anoctadecyl group, a nonadecyl group, an icosyl group, a heneicosyl group,and a docosyl group. The groups having 8 or more carbon atoms arepreferable. Further, these oligomers and polymers may also be used.

The alkenyl group may be substituted or unsubstituted, and specificexamples include: a vinyl group, an allyl group, a butenyl group, apentenyl group, a hexysenyl and group. The groups having 8 or morecarbon atoms are preferable. Further, these oligomers and polymers mayalso be used.

The aryl group may be substituted or unsubstituted, and specificexamples include: a phenyl group, a tril group, a 4-cyanophenyl group, abiphenyl group, an o, m, p-terphenyl groups, a naphthyl group, ananthranil group, a phenanthrenyl group, a fluorenyl group, a9-phenylanthranil group, a 9,10-diphenylanthranil group, and a pyrenylgroup. The groups having 8 or more carbon atoms are preferable. Further,these oligomers and polymers may also be used.

Specific examples of a substituent or unsubstituted alkoxy groupinclude: a methoxy group, an n-butoxy group, a tert-butoxy group, atrichloromethoxy group, and a trifluoromethoxy group. The groups having8 or more carbon atoms are preferable. Further, these oligomers andpolymers may also be used.

Specific examples of a substituted or unsubstituted cycloalkyl groupinclude: a cyclopentyl group, a cyclohexyl group, a norbonan group, anadamantane group, a 4-methylcyclohexyl group, and a 4-cyanocyclohexylgroup. The groups having 8 or more carbon atoms are preferable. Further,these oligomers and polymers may also be used.

Specific examples of a substituent or unsubstituted heterocyclic groupinclude: a pyrrole group, a pyrroline group, a pyrazole group, apyrazoline group, an imidazole group, a triazole group, a pyridinegroup, a pyridazine group, a pyrimidine group, a pyrazine group, atriazine group, an indole group, a benzimidazole group, a purine group,a quinoline group, an isoquinoline group, a cinnoline group, aquinoxaline group, a benzoquinoline group, a fluorenone group, adicyanofluorenone group, a carbazole group, an oxazole group, anoxadiazole group, a thiazole group, a thiadiazole group, a benzoxazolegroup, a benzothiazole group, a benzotriazole group, a bisbenzoxazolegroup, a bisbenzothiazole group, and a bisbenzimidazole group. Theseoligomers and polymers may also be used.

Specific examples of a substituted or unsubstituted acyl group include:a formyl group, an acetyl group, a propionyl group, a butyryl group, anisobutyryl group, a valeryl group, a pivaloyl group, a lauroyl group, amyristoyl group, a palmitoyl group, a stearoyl group, an oxalyl group, amalonyl group, a succinyl group, a glutaryl group, an adipoyl group, apimeroyl group, a suberoyl group, an azelaoyl group, a sebacolic group,an acryloyl group, a propioyl group, a methacryloyl group, a benzoylgroup, a phthaloyl group, an isophthaloyl group, a terephthaloyl group,a naphthoyl group, a toluoyl group, a hydroatropoyl group, an atropoylgroup, a cinnamoyl group, a furoyl group, a tenoyl group, a nicotinoylgroup, an isonicotinoyl group, a glycoloyl group, a lactoyl group, aglyceroyl group, a tartronoyl group, a maloyl group, a tartaroyl group,a tropoyl group, a benzyloyl group, a salicyloyl group, an anisoylgroup, a vanilloyl group, a veratroyl group, a piperoniloyl group, aprotocatequoyl group, a galloyl group, a glyoxyloyl group, a pyruvoylgroup, an acetoacetyl group, a mesooxalyl group, a mesooxalo group, anoxalacetyl group,an oxalaceto group, and a levulinoyl group. These acylgroups may be substituted by fluorine, chlorine, bromine, or iodine. Thegroups having 8 or more carbon atoms are preferable. Further, theseoligomers and polymers may also be used.

Specific combinations of metal alkoxides, metal carboxylates, andfluorinated alcohols for forming the organometallic oxide having thestructure represented by Formula (1) according to the present inventionare exemplified below. However, the present invention is not limited tothem.

The metal alkoxides, metal carboxylates, and fluorinated alcohols (R—OH)are formed into organometallic oxides according to the present inventionby the following Reaction Scheme III. Here, (R′—OH) is exemplified bythe following structures F-1 to F-16.

The metal alkoxides or metal carboxylates according to the presentinvention are exemplified by compounds represented by the M(OR)_(n) orM(OCOR)_(n), and the organometallic oxides according to the presentinvention are combined with the above (R′—OH: F-1 to F-16) to becompounds having structures of the following exemplified compounds Nos.1 to 155 (see exemplified compounds I, II, III and IV). Theorganometallic oxide according to the present invention is not limitedthereto.

(Exemplified Compounds I)

Exemplified Compound Number M(OR)n R′—OH 1 Ti(OiPr)₄ F-1 2 Ti(OiPr)₄ F-23 Ti(OiPr)₄ F-3 4 Ti(OiPr)₄ F-4 5 Ti(OiPr)₄ F-5 6 Ti(OiPr)₄ F-6 7Ti(OiPr)₄ F-7 8 Ti(OiPr)₄ F-8 9 Ti(OiPr)₄ F-9 10 Ti(OiPr)₄ F-10 11Ti(OiPr)₄ F-11 12 Ti(OiPr)₄ F-12 13 Ti(OiPr)₄ F-13 14 Ti(OiPr)₄ F-14 15Ti(OiPr)₄ F-15 16 Ti(OiPr)₄ F-16 17 Ti(OEt)₄ F-1 18 Ti(OEt)₄ F-2 19Ti(OEt)₄ F-3 20 Ti(OEt)₄ F-4 21 Ti(OEt)₄ F-5 22 Ti(OEt)₄ F-6 23 Ti(OEt)₄F-7 24 Ti(OEt)₄ F-8 25 Ti(OEt)₄ F-9 26 Ti(OEt)₄ F-10 27 Ti(OEt)₄ F-11 28Ti(OEt)₄ F-12 29 Ti(OEt)₄ F-13 30 Ti(OEt)₄ F-14 31 Ti(OEt)₄ F-15 32Ti(OEt)₄ F-16 33 Ti(OBu)₄ F-1 34 Ti(OBu)₄ F-2 35 Ti(OBu)₄ F-3 36Ti(OBu)₄ F-4 37 Ti(OBu)₄ F-5 33 Ti(OBu)₄ F-6 39 Ti(OBu)₄ F-7 40 Ti(OBu)₄F-8 41 Ti(OMe)₄ F-1 42 Ti(OMe)₄ F-2 43 Ti(OMe)₄ F-5 44 Ti(OMe)₄ F-13 45Ti(OMe)₄ F-15

(Exemplified Compounds II)

Exemplified Compound Number M(OR)n R′—OH 46 Zr(OiPr)₄ F-1 47 Zr(OiPr)₄F-2 48 Zr(OiPr)₄ F-5 49 Zr(OiPr)₄ F-13 50 Zr(OiPr)₄ F-15 51 Sn(OtBu)₄F-1 52 Sn(OtBu)₄ F-2 53 Sn(OtBu)₄ F-5 54 Sn(OtBu)₄ F-13 55 Sn(OtBu)₄F-15 56 Si(OEt)₄ F-1 57 Si(OEt)₄ F-2 58 Si(OEt)₄ F-5 59 Si(OEt)₄ F-13 60Si(OEt)₄ F-15 61 Si(OBu)₄ F-1 62 Si(OBu)₄ F-2 63 Si(OBu)₄ F-5 64Si(OBu)₄ F-13 65 Si(OBu)₄ F-15 66 Ta(OEt)₅ F-1 67 Ta(OEt)₅ F-2 68Ta(OEt)₅ F-5 69 Ta(OEt)₅ F-13 70 Ta(OEt)₅ F-15 71 Yb(OiPr)₃ F-1 72Yb(OiPr)₃ F-2 73 Yb(OiPr)₃ F-5 74 Yb(OiPr)₃ F-13 75 Yb(OiPr)₃ F-15 76Y(OiPr)₃ F-1 77 Y(OiPr)₃ F-2 78 Y(OiPr)₃ F-5 79 Y(OiPr)₃ F-13 80Y(OiPr)₃ F-15 81 Al(OiPr)₃ F-1 82 Al(OiPr)₃ F-2 83 Al(OiPr)₃ F-5 84Al(OiPr)₃ F-13 85 Al(OiPr)₃ F-15 86 Sr(OiPr)₂ F-1 87 Sr(OiPr)₂ F-2 88Sr(OiPr)₂ F-5 89 Sr(OiPr)₂ F-13 90 Sr(OiPr)₂ F-15

(Exemplified Compounds III)

Exemplified Compound Number M(OR)n R′—OH 91 Mg(OiPr)₂ F-1 92 Mg(OiPr)₂F-2 93 Mg(OiPr)₂ F-5 94 Mg(OiPr)₂ F-13 95 Mg(OiPr)₂ F-15 96 Ba(OiPr)₂F-1 97 Ba(OiPr)₂ F-2 98 Ba(OiPr)₂ F-5 99 Ba(OiPr)₂ F-13 100 Ba(OiPr)₂F-15 101 Ca(OiPr)₂ F-1 102 Ca(OiPr)₂ F-2 103 Ca(OiPr)₂ F-5 104 Ca(OiPr)₂F-13 105 Ca(OiPr)₂ F-15 106 Al(OEt)₃ F-1 107 Al(OEt)₃ F-2 108 Al(OEt)₃F-5 109 Al(OEt)₃ F-13 110 Al(OEt)₃ F-15

(Exemplified Compounds IV)

Exemplified Compound Number M(OCOR)n R′—OH 111 Zn(OCOCH₃)₂ • 2H₂O F-1112 Zn(OCOCH₃)₂ • 2H₂O F-2 113 Zn(OCOCH₃)₂ • 2H₂O F-5 114 Zn(OCOCH₃)₂ •2H₂O F-13 115 Zn(OCOCH₃)₂ • 2H₂O F-15 116 Co(OCOCH₃)₂ F-1 117Co(OCOCH₃)₂ F-2 118 Co(OCOCH₃)₂ F-5 119 Co(OCOCH₃)₂ F-13 120 Co(OCOCH₃)₂F-15 121 In(OCOCH₃)₃ F-1 122 In(OCOCH₃)₃ F-2 123 In(OCOCH₃)₃ F-5 124In(OCOCH₃)₃ F-13 125 In(OCOCH₃)₃ F-15 126 Fe(OCOCH₃)₂ F-1 127Fe(OCOCH₃)₂ F-2 128 Fe(OCOCH₃)₂ F-5 129 Fe(OCOCH₃)₂ F-13 130 Fe(OCOCH₃)₂F-15 131 Mo(OCOCH₃)₂ F-1 132 Mo(OCOCH₃)₂ F-2 133 Mo(OCOCH₃)₂ F-5 134Mo(OCOCH₃)₂ F-13 135 Mo(OCOCH₃)₂ F-15 136 Ni(OCOCH₃)₂ • 4H₂O F-1 137Ni(OCOCH₃)₂ • 4H₂O F-2 138 Ni(OCOCH₃)₂ • 4H₂O F-5 139 Ni(OCOCH₃)₂ • 4H₂OF-13 140 Ni(OCOCH₃)₂ • 4H₂O F-15 141 Pd(OCOCH₃)₂ F-1 142 Pd(OCOCH₃)₂ F-2143 Pd(OCOCH₃)₂ F-5 144 Pd(OCOCH₃)₂ F-13 145 Pd(OCOCH₃)₂ F-15 146Ag(OCOCH₃) F-1 147 Ag(OCOCH₃) F-2 148 Ag(OCOCH₃) F-5 149 Ag(O000H₃) F-13150 Ag(OCOCH₃) F-15 151 Sr(OCOCH₃)₂ F-1 152 Sr(OCOCH₃)₂ F-2 153Sr(OCOCH₃)₂ F-5 154 Sr(OCOCH₃)₂ F-13 155 Sr(OCOCH₃)₂ F-15

The method for producing an organometallic oxide according to thepresent invention is characterized in that it is produced using amixture of a metal alkoxide and a fluorinated alcohol.

As an example of the reaction, the reaction scheme IV of ExemplifiedCompound No. 1 and the structure of the organometallic oxide whenapplied to an organic thin film are shown below.

In the structural formulae below, “Ti” in the part of “O—Ti” further hasa substituent, but is omitted.

The method for producing an organometallic oxide according to thepresent invention may include a method in which a fluorinated alcohol isadded to a metal alkoxide or a metal carboxylate, the mixture is stirredand mixed as a mixed solution, and then water and a catalyst are addedas necessary to react at a predetermined temperature.

When the sol-gel reaction is carried out, in order to accelerate thehydrolysis and polycondensation reaction, a catalyst which can be acatalyst of the hydrolysis and polymerization reaction as shown belowmay be added. The catalyst used as a catalyst for thehydrolysis/polymerization reaction of the sol-gel reaction is a catalystused in the general sol-gel reaction as described in “Advanced Sol-GelMethod Functional Thin Film Preparation Technology” (Hiroshi Hirashima,Research and Development Center, Inc., p. 29) and “Sol-Gel MethodSciences” (Sumio Sakka, AGNE Shofusha, P154). For example, in the caseof an acid catalyst, inorganic and organic acids such as hydrochloricacid, nitric acid, sulfuric acid, phosphoric acid, acetic acid, oxalicacid, tartaric acid, and toluenesulfonic acid; in the case of an alkalicatalyst, alkali metal hydroxides such as ammonium hydroxide, potassiumhydroxide, and sodium hydroxide, tetramethylammonium hydroxide,tetraethylammonium hydroxide, quaternary ammonium hydroxide such astetrabutylammonium hydroxide, amines such as ammonia, triethylamine,tributylamine, morpholine, pyridine, piperidine, ethylenediamine,diethylenetriamine, ethanolamine, diethanolamine, triethanolamine,aminosilanes such as 3-aminopropyltriethoxysilane andN(2-aminoethyl)-3-aminopropyltrimethoxysilane are cited.

The amount of the catalyst used is preferably 2 mol equivalent or less,more preferably 1 mol equivalent or less, with respect to 1 mol of themetal alkoxide or metal carboxylate used as the raw material of theorganometallic oxide. When the sol-gel reaction is performed, thepreferable amount of water added is 40 mol equivalent or less, morepreferably 10 mol equivalent or less, and even more preferably 5 molequivalent or less, with respect to 1 mol of metal alkoxide or metalcarboxylate used as a raw material of the organometallic oxide.

In the present invention, the reaction concentration, the temperature,and the time of the sol-gel reaction are not generally described becausethe kind and the molecular weight of the metal alkoxide or the metalcarboxylate used are mutually related. That is, when the reactiontemperature is set to be high or the reaction time is excessively longin the case where the molecular weight of the alkoxide or the metalcarboxylate is high or the reaction concentration is high, the molecularweight of the reaction product may increase along with the hydrolysis orpolycondensation reaction, resulting in high viscosity or gelation.Therefore, the usual preferred reaction concentration is approximately 1to 50% by mass of the solid content in the solution, more preferably 5to 30%. The reaction temperature is usually from 0 to 150° C.,preferably from 1 to 100° C., more preferably from 20 to 60° C., andpreferably from 1 to 50 hours, depending on the reaction time.

The polycondensate of the organometallic oxide forms an organic thinfilm, and absorbs moisture to release fluorinated alcohol, which is ahydrophobic substance, according to the following reaction scheme V.

In the structural formulae below, “Ti” in the part of “O—Ti” further hasa substituent, but is omitted.

[2] Organic Thin Film

The organic thin film of the present invention is preferably an organicmaterial for an electronic device. The “organic thin film” may bereferred to as a “sealing film” because of its function. However, it isa member different from the “sealing member” of an electronic devicesuch as a gas barrier film or glass, which will be described later.

Examples of the electronic device include organic EL elements, lightemitting diodes (Light Emitting Diode: LEDs), liquid crystal elements,photovoltaic cells (photoelectric converters), touch panels, and colorfilters for liquid crystal displays. In particular, in the presentinvention, it is preferable that the electronic device is an organic ELelement, a solar cell, or a light-emitting diode in view of the effectof the present invention.

In the present invention, an organic material for an electronic devicemeans a solid component of an organic material and does not contain anorganic solvent.

[2.1] Examples of the Use of Organic Thin Films

As an example of use of the organic thin film of the present invention,an example in which the organic thin film is provided in an organic ELelement will be described.

FIG. 1 is a schematic cross-sectional view indicating an example of aconfiguration of an organic EL element of an electronic device of thepresent invention.

In the organic EL element (100), a cathode (105), an organic functionallayer group (106), and a transparent electrode (anode 107) are laminatedon a substrate (101) to form an element (10).

The organic thin film (108) of the present invention is formed so as tocover the element (10), and although it is not essential, it ispreferable that another organic thin film (109) is present between theorganic thin film (108) of the present invention and the element (10) toform a laminated film.

The glass cover or gas barrier film (102) is filled with nitrogen gas,and the glass cover or gas barrier film (102) and the substrate (101)are fixed by an adhesive (103).

In the organic thin film (108) of the present invention, when theorganometallic oxide contained therein is hydrolyzed by moisturepermeated from the adhesive (103) into the device interior, thefluorinated alcohol is generated in an equimolar mole with the quenchedwater molecules, and since the water-repellent function is provided,further penetration of water is prevented.

The other organic thin film (109) is preferably an elution preventingfilm having a blocking function for preventing the generated fluorinatedalcohol from penetrating into the element (10).

[2.2] Details of Organic Thin Film

The organic thin film of the present invention contains, as a maincomponent, the desiccant which releases a hydrophobic substance byabsorbing water. The “main component” means that 70% by mass or more ofthe total mass of the organic thin film is preferably the desiccant,more preferably 80% by mass or more, and particularly preferably 90% bymass or more.

The organic thin film of the present invention can be formed bypreparing a coating solution containing the desiccant of the presentinvention, coating the coating solution on an electronic device, andcoating the coating solution while sintering or irradiating withultraviolet rays to cause polycondensation.

As the organic solvent that may be used when preparing the coatingsolution, for example, a hydrocarbon solvent such as an aliphatichydrocarbon, an alicyclic hydrocarbon, an aromatic hydrocarbon, ahalogenated hydrocarbon solvent, an ether such as an aliphatic ether oran alicyclic ether may be used as appropriate.

The concentration of the drying agent (organometallic oxide) of thepresent invention in the coating solution varies depending on the targetthickness and the pot life of the coating solution, but is preferablyabout 0.2 to 35 mass %. It is also preferable to add a catalyst forpromoting polymerization to the coating solution.

Examples of the coating method of the prepared application solutionsinclude: a wet forming method such as a spray coating method, a spincoating method, a blade coating method, a dip coating method, a castingmethod, a roll coating method, a bar coating method, a die coatingmethod, or a patterning method such as a printing method including aninkjet printing method. These can be used depending on the material.Among these, an inkjet printing method is preferable. The inkjetprinting method is not particularly limited, and a known method may beemployed.

The ejection method of the coating liquid from the inkjet head by theinkjet printing method may be either the on-demand method or thecontinuous method. An on-demand inkjet head may be either anelectrical-mechanical conversion method such as a single-cavity type,double-cavity type, vendor type, piston type, share mode type and sharedwall type, or an electric-heat conversion method such as a thermalinkjet type and a bubble jet (registered trademark) type.

In order to immobilize the organic thin film after coating, it ispreferable to use plasma, ozone or ultraviolet rays capable ofpolymerization reaction at a low temperature, and among ultravioletrays, the use of vacuum ultraviolet rays (referred to as VUV) is afeature of the present invention, and the smoothness of the surface ofthe thin film is improved.

Examples of the means for generating ultraviolet rays in the vacuumultraviolet treatment include a metal halide lamp, a high-pressuremercury lamp, a low-pressure mercury lamp, a xenon arc lamp, a carbonarc lamp, an excimer lamp, and a UV light laser, but excimer lamps arepreferably used although not particularly limited thereto.

Ultraviolet irradiation is compatible with both batch processing andcontinuous processing, and may be appropriately selected depending onthe shape of the base material used. In the case where the base materialforming the organic thin film is in the form of a long film, it may becarried out by continuously irradiating ultraviolet rays in a dryingzone provided with the ultraviolet ray generating source as describedabove while conveying the base material. The time required forultraviolet irradiation is generally from 0.1 second to 10 minutes,preferably from 0.5 second to 3 minutes, depending on the compositionand concentration of the base material and the coating solutioncontaining the desiccant used.

From the viewpoint of forming a uniform and robust thin film, it ispreferable that the radiation dose of the vacuum-ultraviolet ray bewithin the range of 0.1 to 10 J/cm² as the energy received by thecoating film surface. Among these, 1 J/cm² or more is more preferable,and 2 J/cm² or more is more preferable. Further, similarly, from theviewpoint of avoiding excessive ultraviolet irradiation, it ispreferable that 8 J/cm² or less among them, more preferably not morethan 6 J/cm², it is more preferable that 4 J/cm² or less.

In addition, the oxygen concentration at the time of irradiation withvacuum ultraviolet rays (VUV) is preferably 300 to 10,000 volume ppm (1volume %) and more preferably 500 to 5,000 volume ppm. By adjusting theoxygen concentration within such a range, it is possible to prevent theorganic thin film from becoming excessively oxygen-rich and to preventdeterioration of moisture absorption.

It is preferable to use a dry inert gas as a gas other than the oxygenat the time of irradiation with vacuum ultraviolet rays (VUV), and inparticular, it is preferable to use a dry nitrogen gas from theviewpoint of cost.

For details of the vacuum ultraviolet treatment, for example, thecontents described in paragraphs 0055 to 0091 of JP-A No. 2012-086394,paragraphs 0049 to 0085 of JP-A No. 2012-006154, and paragraphs 0046 to0074 of JP-A No. 2011-251460 may be referred to.

When the organic thin film of the present invention is left in anenvironment of 60° C. and 90% RH for 1 hour, it is preferable to measurethe contact angle of pure water under an atmosphere of 23° C. in orderto estimate how much fluorine atoms are oriented on the surface of theorganic thin film, and when the contact angle after leaving at this timeis increased as compared with the contact angle before leaving, thewater repellency is further improved and the sealing property againstmoisture permeation is enhanced.

[Measurement of Contact Angle]

The contact angle may be measured by the following method with referenceto the droplet method described in p 52-53 of “Basics and Theory ofAdhesion” (Nikkan Kogyo Shimbun Co., Ltd.).

Specifically, the contact angle of pure water on the interfaces of theorganic thin films is measured by dropping 1 μL of pure water to thesamples of the organic thin films before and after being left at 60° C.and 90% RH for 1 hour on the basis of JIS-R3257 in an atmosphere of 23°C. and 55% RH using a contact angle meter (trade name: DropMaster DM100,manufactured by Kyowa Interface Scientific Co., Ltd.) and measuring thecontact angle after 1 minute. In the measurement, 10 points are measuredat equal intervals in the direction of the width of the organic thinfilm, and the average value except for the maximum value and the minimumvalue is defined as the contact angle.

The thickness of the organic thin film of the present invention ispreferably in the range of 10 nm to 100 μm in the dry film, morepreferably in the range of 0.1 to 1 μm in order to exhibit the effect asthe sealing film.

[3] Other Organic Thin Film

In the organic thin film of the present invention, it is preferable thatthe organic thin film and other organic thin films are laminatedadjacent to each other to form an organic laminated film.

The other organic thin film is a thin film having a function ofpreventing the fluoride alcohol, which is released from the organic thinfilm of the present invention by absorbing moisture, from eluting andpenetrating into the inside of the electronic device and affecting thelight emission inhibition such as generation of dark spots. Hereinafter,the “other organic thin film” will be described as the “elutionpreventing film”.

The elution preventing film may be formed of an organic materialinsoluble in an alcohol solvent by a vapor deposition method. As theorganic material, many organic EL materials such as a triphenylaminederivative, a carbazole derivative, and a stilbene derivative can beused, and there is no particular limitation.

The elution preventing film may be formed by coating. As a material tobe formed by coating, a thermal curing type or UV curing typesolvent-free monomer is preferable, and particularly, a curing typesilicone monomer is preferable. After the solvent-free monomer isapplied, a solid thin film is formed by thermal curing and/or UV curingto form an anti-elution film.

A getter agent that absorbs moisture and oxygen may be mixed in theelution preventing film.

It is preferable to dispose the prepared coating liquid between theelectronic device (organic functional layer) and the organic thin filmof the present invention, and similarly to the above-mentioned organicthin film, it is preferable to apply the coating liquid by a wet formingmethod such as a spray coating method, a spin coating method, a bladecoating method, a dip coating method, a casting method, a roll coatingmethod, a bar coating method, a die coating method, or a patterningmethod such as a printing method including an inkjet printing method.Among these, an inkjet printing method is preferable.

The thickness of the elution preventing film is preferable in the rangeof 10 nm to 100 μm, more preferably 0.1 to 1 μm, in the dry film inorder to exhibit the effect as the elution preventing film.

The elution preventing film preferably contains a silicone resin fromthe viewpoint of expressing the elution prevention function, andpolydimethylsiloxane, polymethylphenylsiloxane, or polydiphenylsiloxanemay be used as the silicone resin. Furthermore, siloxanes containingfluorine atoms may also be suitably used.

The silicone resin used for the elution preventing film according to thepresent invention may be a low molecular body or a high molecular body.Particular preference is given to oligomers and polymers, and specificexamples include polysiloxane polymers such as polysiloxane compounds,polydimethylsiloxane compounds, and polydimethylsiloxane copolymers.Further, these compounds may be combined.

The compound having the polysiloxane skeleton has a structurerepresented by the following Formula (I), and the effect of preventingelution may be arbitrarily controlled by changing the number ofrepetitions n (a number of 1 or more) and the type of the organicmodification portion in Formula (I).

As an example of changing the type of n or the organic modificationportion in the above Formula (I), for example, a structure representedby the following Formula (II) (x and y are 1 or more and m is an integerof 1 or more representing the number of repetitions) may be given, andthe silicone skeleton may be modified by giving a side chain. The R¹ inFormula (II) includes, for example, a methyl group, an ethyl group, anda decyl group. Examples of R² include a polyether group, a polyestergroup, and an aralkyl group.

In addition, compounds having structures represented by the followingFormula (III) (m is an integer of 1 or more) may also be used, and thesilicone chain is composed of several Si—O bonds, and has an average ofone polyether chain corresponding to R³.

As described above, in any of the compounds having the structurerepresented by Formula (II) and the compounds having the structurerepresented by Formula (III), the control of the surface free energy andthe adjustment of the compatibility may be arbitrarily performed.

(Polysiloxane-Based Compounds)

Examples of polysiloxane-based compounds include: a partial hydrolyzateof silane compounds having hydrolyzable silyl groups suahc astetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane,methyltoxysilane, dimethyldimethoxysilane,dimethyldipropyltriethoxysilane, γ-glycidoxypropyltriethoxysilane,γ-glycidoxypropyldimethoxysilane, γ-glycidoxypropyldiethoxysilane,γ-methacryloxypropyltrimethoxysilane,γ-methacryloxypropyltrimethoxysilane, partial hydrolysates of silanecompounds containing hydrolyzable silyl groups, such as γ-acryloxypropylmethyldimethoxysilane; an organosilica sol in which fine particles ofsilicic anhydride are stably dispersed in an organic solvent; and aproduct obtained by adding the silane compound having radicalpolymerizability to the organosilica sol.

(Polydimethylsiloxane-Based Compounds)

Examples of the polydimethylsiloxane-based compound include:polydimethylsiloxane, alkyl-modified polydimethylsiloxane,carboxy-modified polydimethylsiloxane, amino-modifiedpolydimethylsiloxane, epoxy-modified polydimethylsiloxane,fluorine-modified polydimethylsiloxane, and meth-acrylate-modifiedpolydimethylsiloxane (for example, GUV-235 manufactured by Toa SynthesisCo., Ltd.).

(Polydimethylsiloxane Copolymer)

The polydimethylsiloxane copolymer may be any of a block copolymer, agraft copolymer, and a random copolymer, but a block copolymer and agraft copolymer are preferable.

(Commercial Materials)

The commercially available material is not particularly limited as longas it has a silicon atom, and the following materials may be used, forexample.

Produced by Kyoei Chemical Co., Ltd.: GL-01, GL-02R, GL-03, and GL-04R;

Produced by Nisshin Chemical Co., Ltd.: Silface SAG002, Silface SAG005,Silface SAG008, Silface SAG503A, Surfinol 104E, Surfinol 104H, Surfinol104A, Surfinol 104BC, Surfinol 104DPM, Surfinol 104PA, Surfinol104PG-50, Surfinol 104S, Surfinol 420, Surfinol 440, Surfinol 465,Surfinol 485, and Surfinol SE;

Produced by Shin-Etsu Chemical Co., Ltd.: FA-600, KC-89S, KR-500,KR-516, X-40-9296, KR-513, X-22-161A, X-22-162C, X-22-163, X-22-163A,X-22-164, X-22-164A, X-22-173BX, X-22-174ASX, X-22-176DX, X-22-343,X-22-2046, X-22-2445, X- 22-3939A, X-22-4039, X-22-4015, X-22-4272,X-22-4741, X-22-4952, X-22-6266, KF-50-100cs, KF-96L- lcs, KF-101,KF-102, KF-105, KF-351, KF-352, KF-353, KF-354L, KF-355A, KF-393,KF-615A, F-618, KF-857, KF-859, KF-860, KF-862, KF-877, KF-889, KF-945,KF-1001, KF-1002, KF-1005, KF-2012, KF- 2201, X-22-2404, X-22-2426,X-22-3710, KF-6004, KF-6011, KF-6015, KF-6123, KF-8001, KF-8010,KF-8012, and X-22-9002;

Produced by Toray Dow Corning Co., Ltd.: DOW CORNING 100F ADDITIVE, DOWCORNING 11 ADDITIVE, DOW CORNING 3037 INTERMEDIATE, DOW CORNING 56ADDITIVE, DOW CORNING TORAY Z-6094, DOW CORNING TORAY FZ-2104, DOWCORNING TORAY AY42-119, and DOW CORNING TORAY FZ-2222;

Produced by Kao Co., Ltd.: Emulgen 102KG, Emulgen 104P, Emulgen 105,Emulgen 106, Emulgen 108, Emulgen 109P, Emulgen 120, Emulgen 123P,Emulgen 147, Emulgen 210P, Emulgen 220, Emulgen 306P, Emulgen 320P,Emulgen 404, Emulgen 408, Emulgen 409PV, Emulgen 420, Emulgen 430,Emulgen 705, Emulgen 707, Emulgen 709, Emulgen 1108, Emulgen 1118S-70,Emulgen 1135S-70, Emulgen 2020G-HA, Emulgen 2025G, Emulgen LS-106,Emulgen LS-110, and Emulgen LS114.

It is preferable that the compound is contained within the range of0.005 to 5% by mass with respect to all components except the solvent inthe material constituting the elution preventing film.

[4] Electronic Device

As an example of an organic thin film and an electronic device includingan organic laminated film of the organic thin film and another organicthin film of the present invention, an organic EL display deviceincluding an organic EL element, a photoelectric conversion element, anda solar cell will be described.

[4.1] Organic EL Display Device [Organic EL Element]

An organic EL element suitable for use in the present invention has, ona substrate, an anode and a cathode, and one or more organic functionallayers (also referred to as “organic EL layer” and “organic compoundlayer”) sandwiched between these electrodes.

(Substrate)

The substrate which may be used for the organic EL element (hereinafter,also referred to as a substrate, a supporting substrate, a basematerial, or a supporting substrate) is not particularly limited, and aglass substrate, or a plastic substrate may be used, and may betransparent or opaque. When light is extracted from the substrate side,the substrate is preferably transparent. Examples of the transparentsubstrate preferably used include glass, quartz, and transparent plasticsubstrates.

In order to prevent oxygen or water from entering the substrate, thesubstrate preferably has a thickness of 1 μm or more and a water vaporpermeability of 1 g/(m²·24 h·atm) (25° C.) or less in a test based onJIS Z-0208.

Specific examples of the glass substrate include alkali-free glass, lowalkali glass, and soda lime glass. Alkali-free glass is preferable fromthe viewpoint of small moisture adsorption, but any of these may be usedas long as sufficient drying is performed.

Plastic substrates have recently attracted attention because of theirhigh flexibility, light weight, and resistance to cracking, and becauseof their ability to further reduce the thickness of organic EL elements.

The resin film used as the base material of the plastic substrate is notparticularly limited. Examples thereof include: polyester such aspolyethylene terephthalate (PET), polyethylene naphthalate (PEN),polyethylene, polypropylene, cellophane, cellulose diacetate, cellulosetriacetate (TAC), cellulose acetate butyrate, cellulose acetatepropionate (CAP), cellulose acetate phthalate, cellulose nitrate, etc.,or derivatives thereof, polyvinylidene chloride, polyvinyl alcohol,polyethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate,norbornene resin, polymethyl sulfone, polyether, polyphenesulfone,polyether, polyphenylene sulfonate, etc.polyetherketonimide, polyamide,fluoropolymer, nylon, polymethylmethacrylate, acrylic or polyarylates,and organic-inorganic hybrid resins.

Examples of the organic-inorganic hybrid resin include those obtained bycombining an organic resin and an inorganic polymer obtained by asol-gel reaction, for example, silica, alumina, titania, or zirconia.Among these, a norbornene (or cycloolefin based) resin such as Arton(manufactured by JSR Corporation) or Apel (manufactured by MitsuiChemicals Corporation) is particularly preferable.

Usually produced plastic substrates have relatively high moisturepermeability and may contain moisture inside the substrate. Therefore,when such a plastic substrate is used, it is preferable that a barrierfilm (also referred to as a “gas barrier film” or a “water vapor sealingfilm”) for suppressing entry of water vapor or oxygen is provided on theresin film to form a gas barrier film.

The material of the barrier film is not particularly limited, and aninorganic material, an organic material coating, or a hybrid of both isused. A coating may be formed, preferably a barrier film having amoisture vapor transmission rate (25±0.5° C., 90±2% RH) of 0.01 g/(m²·24h) or less as measured by a method conforming to JIS K 7129-1992, andpreferably a high barrier film having an oxygen transmission rate of1×10⁻³ mL/m²·24 h·atm) or less as measured by a method conforming to JISK 7126-1987 and a moisture vapor transmission rate of 1×10⁻⁵ g/(m²·24 h)or less as measured by a method conforming to JIS K 7126-1987.

The material constituting the barrier film is not particularly limitedas long as it has a function of suppressing penetration of moisture oroxygen which causes deterioration of the element, and, for example, aninorganic substance such as a metal oxide, a metal oxynitride, or ametal nitride, an organic substance, or a hybrid material of both may beused.

Examples of the metal oxide, metal oxynitride, or metal nitride includesilicon oxide, titanium oxide, indium oxide, tin oxide, indium tin oxide(ITO), metal oxides such as aluminum oxide, metal nitrides such assilicon nitride, and metal oxynitrides such as silicon oxynitride andtitanium oxynitride.

Further, in order to improve the fragility of the film, it is morepreferable to have a laminated structure of these inorganic layers andlayers made of an organic material. The stacking order of the inorganiclayer and the organic layer is not particularly limited, but it ispreferable that both layers are alternately stacked a plurality oftimes.

The method of providing the barrier film on the resin film is notparticularly limited, and any method may be used; for example, a vacuumevaporation method, a sputtering method, a reactive sputtering method, amolecular beam epitaxy method, a cluster ion beam method, an ion platingmethod, a plasma polymerization method, an atmospheric pressure plasmapolymerization method, a CVD method (for example, a plasma CVD method, alaser CVD method, a thermal CVD method, or the like), a coating method,or a sol-gel method may be used. Among these methods, a method by plasmaCVD process at or near atmospheric pressure is preferable from theviewpoint that a dense film may be formed.

Examples of the opaque substrate include a metal plate such as aluminumor stainless steel, a film, an opaque resin substrate, and a ceramicsubstrate.

(Anode)

As the anode of the organic EL element, a metal having a high workfunction (4 eV or more), an alloy, an electrically conductive compoundof a metal, or a mixture thereof is preferably used as an electrodematerial.

Here, the “electrically conductive compound of metal” refers to acompound of metal and another substance having electrical conductivity,and specifically refers to, for example, an oxide of metal or a halidehaving electrical conductivity.

Specific examples of such electrode materials include metals such as Au,conductive transparent materials such as CuI, indium-tin oxide (ITO),SnO₂, and ZnO. The anode may be manufactured by forming a thin film ofthese electrode materials on the substrate by a known method such asevaporation or sputtering.

In addition, a pattern of a desired shape may be formed on the thin filmby a photolithography method, or in a case where a pattern accuracy isnot required to a large extent (about 100 μm or more), the pattern maybe formed through a mask of a desired shape at the time of deposition orsputtering of the electrode material.

When light emission is extracted from the anode, it is desirable thatthe light transmittance be greater than 10%. The sheet resistance as theanode is preferably several hundred Ω/sq. or less. Further, the filmthickness of the anode is usually selected in the range of 10 nm to 1μm, preferably 10 to 200 nm, depending on the material constituting theanode.

(Organic Functional Layer)

The organic functional layer (also referred to as “organic EL layer” or“organic compound layer”) includes at least a light-emitting layer, andthe light-emitting layer broadly refers to a layer that emits light whena current is passed through an electrode composed of a cathode and ananode, and specifically refers to a layer containing an organic compoundthat emits light when a current is passed through an electrode composedof a cathode and an anode.

The organic EL element used in the present invention may have a holeinjection layer, an electron injection layer, a hole transport layer,and an electron transport layer in addition to the light-emitting layer,if necessary, and these layers are sandwiched between a cathode and ananode.

Specifically, the following structures are cited.

(i) Anode/light-emitting layer/cathode(ii) Anode/hole injection layer/light-emitting layer/cathode(iii) Anode/light-emitting layer/electron injection layer/cathode(iv) Anode/hole injection layer/light-emitting layer/electron injectionlayer/cathode(v) Anode/hole injection layer/hole transport layer/light-emittinglayer/electron transport layer/electron injection layer/cathode(vi) Anode/hole transport layer/light-emitting layer/electron transportlayer/cathode.

Further, a cathode buffer layer (e.g., lithium fluoride) may be insertedbetween the electron injection layer and the cathode, and an anodebuffer layer (e.g., copper phthalocyanine) may be inserted between theanode and the hole injection layer.

(Light-Emitting Layer)

The light-emitting layer is a layer that emits light by recombination ofelectrons and holes injected from an electrode or an electron transportlayer or a hole transport layer, and a portion that emits light may bewithin the layer of the light-emitting layer or at an interface betweenthe light-emitting layer and an adjacent layer. The light-emitting layermay be a layer having a single composition, or may have a multilayerstructure including a plurality of layers having the same or differentcompositions.

The light-emitting layer itself may be provided with functions such as ahole injection layer, an electron injection layer, a hole transportlayer, and an electron transport layer. That is, the light-emittinglayer may be provided with at least one of the following functions: (1)an injection function capable of injecting holes through the anode orthe hole injection layer and injecting electrons from the cathode or theelectron injection layer when an electric field is applied; (2) atransport function capable of moving injected charges (electrons andholes) by an electric field force; and (3) a light emitting function ofproviding a field for recombination of electrons and holes inside thelight-emitting layer and connecting the recombination of electrons andholes to light emission. Note that the light-emitting layer may have adifference between the ease of injecting holes and the ease of injectingelectrons, and may have a large or small transport function representedby the mobility of holes and electrons; however, it is preferable thatthe light-emitting layer have a function of transferring at least one ofthe charges.

The type of the light-emitting material used for this light-emittinglayer is not particularly limited, and conventionally knownlight-emitting materials in organic EL elements may be used. Such alight emitting material is mainly an organic compound, and depending ona desired color tone, for example, a compound described in Macromol.Symp. Vol. 25, pages 17 to 26 may be given. The light-emitting materialmay be a polymer material such as p-polyphenylenevinylene orpolyfluorene. Further, a polymer material having the light emittingmaterial introduced into a side chain or a polymer material having thelight emitting material as a polymer main chain may be used.

Note that, as described above, since the light-emitting material mayhave a hole injection function or an electron injection function inaddition to the light-emitting performance, most of a hole injectionmaterial or an electron injection material which will be described latermay be used as the light-emitting material.

In the layer constituting the organic EL element, when the layer iscomposed of two or more kinds of organic compounds, the main componentis referred to as a host and the other components are referred to asdopants, and when the host and the dopant are used in combination in thelight-emitting layer, the mixing ratio of the dopant of thelight-emitting layer to the host compound which is the main component(hereinafter also referred to as the light-emitting dopant) ispreferably less than 0.1 to 30 mass %.

There are two types of dopants used for the light-emitting layer,namely, a fluorescent dopant that emits fluorescence and aphosphorescent dopant that emits phosphorescence.

Representative examples of the fluorescent dopant include coumarin-baseddyes, pyran-based dyes, cyanine-based dyes, croconium-based dyes,squarium-based dyes, oxobenzanthracene-based dyes, fluorescein-baseddyes, rhodamine-based dyes, pyrylium-based dyes, perylene-based dyes,stilbene-based dyes, polythiophene-based dyes, rare earth complex-basedphosphors, and other known fluorescent compounds.

In the present invention, it is preferable that at least one lightemitting-layer contains a phosphorescent compound.

In the present invention, a phosphorescent compound is a compound inwhich light emission from an excited triplet is observed, and aphosphorescent quantum yield is 0.001 or more at 25° C.

The phosphorescence quantum yield is preferably 0.01 or more, morepreferably 0.1 or more. The phosphorescence quantum yield may bemeasured by the method described on page 398 (1992 edition, Maruzen) ofSpectroscopy II of Experimental Chemical Course 7, 4th edition. Althoughthe phosphorescence quantum yield in solution may be measured usingvarious solvents, the phosphorescent compound used in the presentinvention only needs to achieve the above-mentioned phosphorescentquantum yield in any of the solvents.

The phosphorescent dopant is a phosphorescent compound, a representativeexample of which is preferably a complex compound containing a metal ofgroup 8 to 10 in the periodic table of the elements, and more preferablyan iridium compound, osmium compound, rhodium compound, palladiumcompound, or platinum compound (platinum complex compound), among whichis preferably an iridium compound, rhodium compound, platinum compound,and most preferably an iridium compound.

Examples of the dopant are compounds described in the followingdocuments or patent publications: J. Am. Chem. Soc. Vol. 123, 4304-4312,WO 2000/70655, WO 2001/93642, WO 2002/02714, WO 2002/15645, WO2002/44189, WO 2002/081488, JP-A 2002-280179, JP-A 2001-181617, JP-A2002-280180, JP-A 2001-247859, JP-A 2002-299060 JP-A 2002-332292, JP-A2002-83684, JP-A 2002-540572, JP-A 2002-117978, and JP-A 2002-338588,JP-A 2002-170684, JP-A 2002-50483, JP-A 2002-100476, JP-A 2002-173674,JP-A 2002-359082, JP-A 2002-175884, JP-A 2002-363552, JP-A 2002-184582,JP-A 2003-7469, JP-A 2002-525808, JP-A 2003-7471, JP-A 2002-525833, JP-A2003-31366, JP-A 2002-2264495, JP-A 2002-234894 JP-A 2002-62824, JP-A2002-100474, JP-A 2002-203679, JP-A 2002-343572, and JP-A 2002-203678.

Only one type of light-emitting dopant may be used, or a plurality oftypes may be used, and a light-emitting element having a plurality oflight-emitting maximum wavelengths may be configured by simultaneouslyextracting light emitted from these dopants. For example, both aphosphorescent dopant and a fluorescent dopant may be added. In the casewhere an organic EL element is formed by stacking a plurality oflight-emitting layers, the light-emitting dopants contained in therespective layers may be the same or different, or may be a single typeor a plurality of types.

Furthermore, a polymer material in which the light-emitting dopant isintroduced into a polymer chain or the light-emitting dopant is used asa main chain of a polymer may be used.

Examples of the host compound include those having a basic skeleton suchas carbazole derivatives, triarylamine derivatives, aromatic boranederivatives, nitrogen-containing heterocyclic compounds, thiophenederivatives, furan derivatives, and oligoarylene compounds, and electrontransport materials and hole transport materials described later arealso suitable examples thereof.

In the case of applying to a blue or white light-emitting element, adisplay device, and a lighting device, it is preferable that the maximumfluorescence wavelength of the host compound is 415 nm or less, and inthe case of using a phosphorescent dopant, it is more preferable thatthe 0-0 band of phosphorescence of the host compound is 450 nm or less.As the light-emitting host, a compound which has a hole transportingability and an electron transporting ability and prevents a longerwavelength of light emission and has a high Tg (glass transitiontemperature) is preferable.

As a specific example of the light emitting host, for example, compoundsdescribed in the following documents are suitable.

JP-A 2001-257076, JP-A 2002-308855, JP-A 2001-313179, JP-A 2002-319491,JP-A 2002-334786, JP-A 2002-8860, JP-A 2002-334787, JP-A 2002-15871,JP-A 334788, JP-A 2002-43056, JP-A 334789, JP-A 2002-75645, JP-A2002-338579, JP-A 2002-34445, JP-A 2002, JP-A 2002-34786, and JP-A2002-2002 JP-A 2002-231453, JP-A 2003-3165, JP-A 2002-234888, JP-A2003-27048, JP-A 2002-255934, JP-A 2002-260861, JP-A 2002-280183, JP-A2002-299060, JP-A 2002-302516, JP-A 2002-305083, JP-A 2002-305084, andJP-A 2002-308837.

The light-emitting dopant may be dispersed throughout the layercontaining the host compound or may be partially dispersed. A compoundhaving another function may be added to the light-emitting layer.

The light-emitting layer may be formed by thinning using the abovematerials by a known method such as a vacuum evaporation method, a spincoating method, a casting method, an LB (Langmuir-Blodgett) method, aninkjet method, or a printing method, and it is particularly preferablethat the formed light-emitting layer is a molecularly deposited film.

Here, the molecular deposition film is a thin film deposited and formedfrom the vapor phase state of the compound, or a film solidified andformed from the molten state or the liquid phase state of the compound.Usually, this molecular deposited film and a thin film (molecularcumulative film) formed by the LB method may be distinguished from eachother by a difference between an aggregated structure and a higher-orderstructure or a functional difference caused by the difference.

In the present invention, it is preferable to use the phosphorescentdopant and the host compound, which are the above-mentionedlight-emitting materials, as the organic material for an electronicdevice of the present invention. That is, it is preferable that thelight-emitting layer is formed by coating a solution (composition formanufacturing an electronic device) containing the phosphorescent dopantand the host compound, the organic solvent, and the cellulose nanofibersby spin coating, casting, inkjet, spray, printing, or slot type coater,because the light-emitting layer formed of the molecular deposition filmcan be formed. Among them, the inkjet printing method is preferable fromthe viewpoint that a homogeneous film is easily obtained and a pinholeis hardly generated.

In the coating solution containing the phosphorescent dopant, the hostcompound, the organic solvent, and the cellulose nanofiber, it ispreferable that the dissolved carbon dioxide concentration in theorganic solvent is 1 ppm to the saturation concentration in the organicsolvent under the atmospheric pressure condition at 50° C. or less.Means for setting the dissolved carbon dioxide concentration in theabove range include a method of bubbling carbon dioxide gas into asolution containing a phosphorescent dopant, a host compound, and anorganic solvent, or a supercritical chromatography method using asupercritical fluid containing an organic solvent and carbon dioxide.

(Hole Injection Layer and Hole Transport Layer)

The hole injection material used for the hole injection layer has eitherhole injection or electronic barrier properties. The hole transportmaterial used for the hole transport layer has electronic barrierproperties and functions to transport holes to the light-emitting layer.Therefore, in the present invention, the hole transport layer isincluded in the hole injection layer.

The hole injection material and the hole transport material may be anorganic substance or an inorganic substance. Specific examples includeconductive polymer oligomers such as triazole derivatives, oxadiazolederivatives, imidazole derivatives, polyarylalkane derivatives,pyrazoline derivatives, pyrazolone derivatives, phenylenediaminederivatives, arylamine derivatives, amino-substituent chalconederivatives, oxazole derivatives, styrylanthracene derivatives,fluorenone derivatives, hydrazone derivatives, stilbene derivatives,silazane derivatives, aniline copolymers, porphyrine compounds, andthiophene oligomers. Of these, arylamine derivatives and porphyrincompounds are preferred.

Among the arylamine derivatives, aromatic tertiary amine compounds andstyrylamine compounds are preferable, and aromatic tertiary aminecompounds are more preferable.

Representative examples of such aromatic tertiary amine compounds andstyrylamine compounds are N,N,N′,N′-tetraphenyl-4,4′-diaminophenyl;N,N′-diphenyl-N,N′-bis(3-methylphenyl)- [1,1′-biphenyl]-4,4′-diamine(TPD); 2,2-bis(4-di-p-trilaminophenyl)propane; 1,1-bis(4-di-p-trilaminophenyl)cyclohexane;N,N,N′,N′-tetra-p-tolyl-4,4′-diaminobiphenyl;1,1-bis(4-di-p-tolylaminophenyl)-4-phenylcyclohexane;bis(4-dimethylamino-2-methylphenyl)phenylmethane;bis(4-di-p-tolylaminophenyflphenylmethane;N,N′-diphenyl-N,N′-di(4-methoxyphenyl)-4,4′-diaminobiphenyl;N-tetraphenyl-4,4′-diaminodiphenyl ether;4,4′-bis(diphenylamino)biphenyl; N,N,N-tri(p-tolyl)amine;4-(di-p-tolylamino)styryl; 4-N,N-diphenylamino-(2-diphenylvinyflbenzene;3-methoxy-4′-N,N-diphenylaminostyrben; N-phenylcarbazole; and thosehaving two fused aromatic rings in their discs, e.g.,4,4′-bis(N′-phenyflalpha, described in U.S. Pat. No. 5,061,569. JP-A4-308688 describes triphenylamine units connected in a three-star burstform, such as4,4′,4″-tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine (MTDATA).Inorganic compounds such as p-type-Si and p-type-SiC may also be used asthe hole injection material.

In the present invention, the hole transport material of the holetransport layer preferably has a fluorescence maximum wavelength of 415nm or less. That is, as the hole transport material, a compound whichhas a hole transporting ability, prevents a longer wavelength of lightemission, and has a high Tg is preferable.

The hole injection layer and the hole transport layer may be formed bythinning the hole injection material and the hole transport material by,for example, a known method such as a vacuum evaporation method, a spincoating method, a casting method, an LB method, an inkjet method, or aprinting method.

In the present invention, it is preferable to use the above holeinjection material and hole transport material as the organic materialfor an electronic device of the present invention. Then, the holeinjection material and the hole transport material, an organic solvent,a solution containing cellulose nanofiber (composition for electronicdevice fabrication), by a spin coating method, a casting method, an inkjet method, a spray method, or a printing method, it is preferable toform by applying a slot-type coater method. Among them, the inkjetprinting method is preferable from the viewpoint that a homogeneous filmis easily obtained and a pinhole is hardly generated.

The thickness of the hole injection layer and the hole transport layeris not particularly limited, but is usually about 5 nm to 5 μm. The holeinjection layer and the hole transport layer may have a one-layerstructure composed of one kind or two or more kinds of the abovematerials, respectively, or may have a multilayer structure composed ofa plurality of layers having the same composition or differentcompositions. When both the hole injection layer and the hole transportlayer are provided, a different material from the above materials isusually used, but the same material may be used.

(Electron Injection Layer and Electron Transport Layer)

The electron injection layer may have any function as long as it has afunction of transmitting electrons injected from the cathode to thelight-emitting layer, and any of conventionally known compounds may beselected and used as a material thereof.

Examples of materials used for the electron injection layer (hereinafteralso referred to as electron injection materials) includenitro-substituent fluorene derivatives, diphenylquinone derivatives,thiopyrandioxide derivatives, heterocyclic tetracarboxylic anhydridessuch as naphthaleneperylene, carbodiimide, freorenylidene methanederivatives, anthraquinodimethane and anthrone derivatives, andoxadiazole derivatives.

Further, a series of electron-transmitting compounds described in JP-A59-194393 is disclosed as a material for forming a light-emitting layerin the publication, the present inventors as a result of their studies,it has been found that can be used as an electron injection material.Further, in the oxadiazole derivative, a thiadiazole derivative in whichan oxygen atom of an oxadiazole ring is substituted with a sulfur atom,or a quinoxaline derivative having a quinoxaline ring known as anelectron withdrawing group can also be used as an electron injectingmaterial.

Metal complexes of 8-quinolinol derivatives, such astris(8-quinolinol)aluminum (Alq₃),tris(5,7-dichloro-8-quinolinol)aluminum,tris(5,7-dibromo-8-quinolinol)aluminum,tris(2-methyl-8-quinolinol)aluminum,tris(5-methyl-8-quinolinol)aluminum, bis(8-quinolinol)zinc (Znq), andmetal complexes in which the central metal of these metal complexes isreplaced with In, Mg, Cu, Ca, Sn, Ga, or Pb, can also be used aselectron-injection materials.

In addition, metal-free, metal phthalocyanine, or a material whoseterminal is substituted with an alkyl group or a sulfonic acid group maybe preferably used as the electron injecting material. Like the holeinjection layer, an inorganic semiconductor such as n-type-Si orn-type-SiC can also be used as an electron injection material.

The preferable compound used for the electron transport layer preferablyhas a fluorescence maximum wavelength of 415 nm or less. That is, thecompound used for the electron transport layer is preferably a compoundwhich has an electron transporting ability, prevents a longer wavelengthof light emission, and has a high Tg.

The electron injection layer may be formed by thinning the electroninjection material by, for example, a known method such as a vacuumevaporation method, a spin coating method, a casting method, an LBmethod, an inkjet method, or a printing method.

In the present invention, it is preferable to use the above-mentionedelectron injection material as an organic material for an electronicdevice of the present invention.

Then, the solution containing the electron injection material, theorganic solvent, and the cellulose nanofiber (composition for preparingan electronic device) is preferably subjected to formation of film by aspin coating method, a casting method, an inkjet method, a spray method,a printing method, or a slot-type coater method. Among them, the inkjetmethod is preferable from the viewpoint that a uniform film is easilyobtained and pinholes are hardly generated.

The thickness of the electron injection layer is not particularlylimited, but is usually selected in the range of 5 nm to 5 μm. Theelectron injection layer may have a one-layer structure composed of onekind or two or more kinds of these electron injection materials, or mayhave a multilayer structure composed of a plurality of layers of thesame composition or different kinds of composition.

In this specification, when the ionization energy of the electroninjection layer is larger than that of the light-emitting layer, theelectron injection layer is particularly referred to as an electrontransport layer. Therefore, in the present specification, the electrontransport layer is included in the electron injection layer.

The electron transport layer is also referred to as a hole blockinglayer, and is described in, for example, WO 2000/70655, JP-A2001-313178, JP-A 11-204258, and JP-A 11-204359, and page 237 of“Organic EL element and its industrialization front line (issued by NTSCorporation, published Nov. 30, 1998). In particular, in a so-called“phosphorescent light-emitting element” in which an orthometal complexdopant is used for a light-emitting layer, it is preferable to adopt aconfiguration having an electron transport layer (hole blocking layer)as in the above (v) and (vi).

(Buffer Layer)

A buffer layer (electrode interface layer) may be present between theanode and the light-emitting layer or the hole injecting layer, andbetween the cathode and the light-emitting layer or the electroninjecting layer.

The buffer layer is a layer between electrodes and organic layers fordriving voltage reduction and luminescence efficiency improvement. It isdescribed in detail in Chapter 2, Electrode Materials (page 123-166) ofthe second edition of the Organic EL Elements and theirIndustrialization Frontiers (published November 30, 1998) and includesthe anodal buffer layer and the cathodal buffer layer.

The details of the anode buffer layer are also described in JP-A9-45479, JP-A 9-260062, and JP-A 8-288069, and specific examples includea phthalocyanine buffer layer typified by copper phthalocyanine, anoxide buffer layer typified by vanadium oxide, an amorphous carbonbuffer layer, a polymer buffer layer using a conductive polymer such aspolyaniline (emeraldine) or polythiophene.

The cathode buffer layer is also described in detail in JP-A 6-325871,JP-A 9-17574, and JP-A 10-74586. Specifically, a metal buffer layerrepresented by strontium or aluminum, an alkali metal compound bufferlayer represented by lithium fluoride, an alkaline earth metal compoundbuffer layer represented by magnesium fluoride, and an oxide bufferlayer represented by aluminum oxide.

The buffer layer is desirably a very thin film, and the thicknessthereof is preferably in the range of 0.1 to 100 nm, depending on thematerial. In addition to the above-mentioned basic constituent layers,layers having other functions may be appropriately stacked as necessary.

(Cathode)

As described above, as the cathode of the organic EL element, a metalhaving a small work function (less than 4 eV) (hereinafter, referred toas an electronic injecting metal), an alloy, an electrically conductivecompound of a metal, or a mixture thereof is generally used as anelectrode material.

Specific examples of such electrode materials include sodium, magnesium,lithium, aluminum, indium, rare earth metals, sodium-potassium alloys,magnesium/copper mixtures, magnesium/silver mixtures, magnesium/aluminummixtures, magnesium/indium mixtures, aluminum/aluminum oxide (Al₂O₃)mixtures, and lithium/aluminum mixtures.

In the present invention, the materials listed above may be used as theelectrode material of the cathode, but it is preferable that the cathodecontains a Group 13 metal element. That is, in the present invention, asdescribed later, the surface of the cathode is oxidized with an oxygengas in a plasma state to form an oxide film on the surface of thecathode, whereby further oxidation of the cathode may be prevented anddurability of the cathode may be improved.

Therefore, the electrode material of the cathode is preferably a metalhaving a preferable electronic injecting property required for thecathode and capable of forming a dense oxide film.

Specific examples of the electrode material of the cathode containingthe Group 13 metallic element include aluminum, indium, amagnesium/aluminum mixture, a magnesium/indium mixture, analuminum/aluminum oxide (Al₂O₃) mixture, and a lithium/aluminum mixture.The mixing ratio of the components of the above mixture may be aconventionally known ratio as the cathode of the organic EL element, butis not particularly limited thereto. The cathode may be manufactured byforming a thin film of the electrode material on the organic compoundlayer (organic EL layer) by a method such as evaporation or sputtering.

The sheet resistance as the cathode is preferably several hundred Ω/sq.or less, and the film thickness is usually selected in the range of 10nm to 1 μm, preferably 50 to 200 nm. In order to transmit the emittedlight, it is preferable to make either the anode or the cathode of theorganic EL element transparent or translucent in order to improve theluminous efficiency.

[Manufacturing Method of Organic EL Element]

As an example of a method of manufacturing an organic EL element, amethod of manufacturing an organic EL element composed of an anode, ahole injection layer, a hole transport layer, a light-emitting layer, anelectron transport layer, an electron injection layer, and a cathodewill be described.

First, a thin film made of a desired electrode material, for example, amaterial for an anode is formed on a suitable base material by a methodsuch as evaporation or sputtering so as to have a thickness of 1 μm orless, preferably 10 to 200 nm, to produce an anode. Next, an organiccompound thin film (organic thin film) of a hole injection layer, a holetransport layer, a light-emitting layer, an electron transport layer, anelectron injection layer, and a hole blocking layer, which are elementmaterials, is formed thereon.

As a method for thinning these organic thin films, as described above,there are spin coating, casting, inkjet printing, spraying, vapordeposition, printing, and slot coating, but an inkjet printing method ispreferable in that a uniform film is easily obtained and a pinhole isnot easily generated, and in the present invention, a composition formanufacturing an electronic device of the present invention can be used.

Alternatively, a different film formation method may be applied to eachlayer. In the case of employing an evaporation method for filmformation, the evaporation conditions differ depending on the type ofthe compound used, but it is generally preferable to select theevaporation conditions in the range of boat heating temperature of 50 to450° C., vacuum degree of 10⁻⁶ to 10⁻² Pa, evaporation rate of 0.01 to50 nm/sec, substrate temperature of −50 to 300° C., and thickness of 0.1nm to 5 μm.

After these layers are formed, a thin film made of a substance for acathode is formed thereon to a thickness of 1 μm or less, preferably inthe range of 50 to 200 nm, by a method such as evaporation orsputtering, for example, and a cathode is provided, whereby a desiredorganic EL element is obtained. It is preferable that the organic ELelement is manufactured consistently from the hole injection layer tothe cathode by one evacuation, but a different film formation method maybe performed by taking out the organic EL element in the middle. In thiscase, it is necessary to take care of performing the operation under adry inert gas atmosphere.

[Sealing of Organic EL Element]

The sealing means of the organic EL element is not particularly limited,and for example, a method of sealing the outer peripheral portion of theorganic EL element with a sealing adhesive and then arranging a sealingmember so as to cover the light emitting region of the organic ELelement can be cited.

Examples of the sealing adhesive include a photocurable and athermosetting adhesive having a reactive vinyl group of an acrylic acidoligomer, a methacrylic acid oligomer, and a moisture curable adhesivesuch as 2-cyanoacrylate acid ester. Further, it is possible to include athermal and chemical curing type (two-liquid mixing) such as an epoxysystem. Also, hot melt type polyamides, polyesters, and polyolefins maybe mentioned. In addition, an ultraviolet curable epoxy resin adhesiveof a cationic curable type may be mentioned.

As the sealing member, a polymer film and a metal film may be preferablyused from the viewpoint of making the organic EL element thinner. In thecase of a polymer film, it is preferable to provide the aforementionedgas barrier property.

Examples of the sealing structure include a structure in which a spacebetween the organic EL element and the sealing member is hollow, and afilling and sealing structure in which a sealing material such as anadhesive is filled between the organic EL element and the sealingmember.

In addition to the sealing adhesive, an inert gas such as nitrogen orargon, or an inert liquid such as a fluorocarbon or silicone oil may beinjected into the gap between the sealing member and the light emittingregion of the organic EL element in the gas phase or the liquid phase.In addition, a gap between the sealing member and the display region ofthe organic EL element may be a vacuum, an inert gas may be sealed inthe gap, or a desiccant may be disposed.

[Organic EL Display Device]

In an organic EL display device using the organic EL element describedabove (hereinafter, also referred to as a display device), if a shadowmask is provided only when a light-emitting layer is formed and theother layers are commonly used, patterning of a shadow mask isunnecessary, and a film may be formed on one surface by an evaporationmethod, a casting method, a spin coating method, an inkjet method, or aprinting method.

When patterning is performed only on the light-emitting layer, themethod is not limited, but it is preferable to use a vapor depositionmethod, an inkjet printing method, or a printing method. In the case ofusing an evaporation method, patterning using a shadow mask ispreferable.

Alternatively, the cathode, the electron injection layer, the electrontransport layer, the light-emitting layer, the hole transport layer, thehole injection layer, and the anode may be manufactured in this order byreversing the manufacturing order.

When a DC voltage is applied to the display device thus obtained, lightemission can be observed by applying a voltage of about 2 to 40 V withthe positive polarity of the anode and the negative polarity of thecathode. In addition, even if a voltage is applied with the oppositepolarity, no current flows and no light emission occurs. Further, whenan AC voltage is applied, light is emitted only when the anode is inthe + state and the cathode is in the − state. The waveform of theapplied alternating current may be arbitrary.

The display device may be used as a display device, a display, orvarious light emitting sources. In the display device and the display,full-color display is possible by using three kinds of organic ELelements of blue, red, and green light emission.

Examples of the display device and the display include a television, apersonal computer, a mobile device, an AV device, a teletext display,and an information display in an automobile. In particular, it may beused as a display device for reproducing a still image or a staticimage, and the driving method for use as a display device forreproducing a moving image may be either a simple matrix method or anactive matrix method.

Examples of the light-emitting light source include, but are not limitedto, home lighting, in-vehicle lighting, a backlight for a timepiece or aliquid crystal, a signboard advertisement, a traffic light, a lightsource of an optical storage medium, a light source of anelectrophotographic copying machine, a light source of an opticalcommunication processor, and a light source of an optical sensor.

Further, the organic EL element according to the present invention maybe used as an organic EL element having a resonator structure.

The purpose of use of the organic EL element having such a resonatorstructure includes, but is not limited to, a light source of an opticalstorage medium, a light source of an electrophotographic copyingmachine, a light source of an optical communication processor, and alight source of an optical sensor. Laser oscillation may also be used inthe above applications.

The organic EL element according to the present invention may be used asa kind of lamp such as an illumination light source or an exposure lightsource, or may be used as a projection device of a type for projectingan image or a display device of a type for directly viewing a stillimage or a static image. The driving method for use as a display devicefor moving image reproduction may be either a simple matrix (passivematrix) method or an active matrix method. Alternatively, by using twoor more kinds of the organic EL elements of the present invention havingdifferent emission colors, a full-color display device may bemanufactured.

[4.2] Photoelectric Conversion Element and Solar Cell

The organic thin film or the organic laminated film of the organic thinfilm and other organic thin films of the present invention is preferablyapplied, for example, as a sealing film of an organic functional layerof a photoelectric conversion element.

Hereinafter, details of the photoelectric conversion element and thesolar cell will be described. In the drawing, the organic thin film orthe organic multilayer film of the present invention is omitted, but theentire device is covered with the organic thin film or the organicmultilayer film similarly to the organic EL element described above.

FIG. 2 is a cross-sectional view indicating an example of a solar cellhaving a single configuration composed of a bulk heterojunction typeorganic photoelectric conversion element, in which a bulk heterojunctionlayer is formed as one layer.

In FIG. 2, in a bulk heterojunction type organic photoelectricconversion element (200), a transparent electrode (anode 202), a holetransport layer (207), a photoelectric conversion unit (204) of a bulkheterojunction layer, an electron transport layer (also referred to as abuffer layer) (208), and a counter electrode (cathode 203) aresequentially stacked on one surface of a substrate (201).

The substrate (201) is a member for holding the transparent electrode(202), the photoelectric conversion portion (204), and the counterelectrode (203) which are sequentially stacked. In the presentembodiment, since the light to be photoelectrically converted isincident from the substrate (201) side, it is preferable that thesubstrate (201) is a member capable of transmitting the light to bephotoelectrically converted, that is, transparent to the wavelength ofthe light to be photoelectrically converted. As the substrate 201, forexample, a glass substrate or a resin substrate. The substrate (201) isnot essential, and for example, the organic photoelectric conversionelement (200) of the bulk heterojunction type may be configured byforming the transparent electrode (202) and the counter electrode (203)on both surfaces of the photoelectric conversion unit (204).

The photoelectric conversion unit (204) is a layer for converting lightenergy into electric energy, and includes a bulk heterojunction layer inwhich a p-type semiconductor material and an n-type semiconductormaterial are uniformly mixed. The p-type semiconductor materialfunctions relatively as an electron donor (donor), and the n-typesemiconductor material functions relatively as an electron acceptor(acceptor). Here, an electron donor and an electron acceptor are “anelectron donor and an electron acceptor in which electrons move from anelectron donor to an electron acceptor when light is absorbed to form apair of holes and electrons (charge separation state)” and donate oraccept electrons by a photoreaction rather than simply donating oraccepting electrons like an electrode.

In FIG. 2, light incident from the transparent electrode (202) throughthe substrate (201) is absorbed by an electron acceptor or an electrondonor in the bulk heterojunction layer of the photoelectric conversionunit (204), and electrons move from the electron donor to the electronacceptor, thereby forming a pair of holes and electrons (chargeseparation state). The generated charges are transported to differentelectrodes by an internal electric field, for example, a potentialdifference between the transparent electrode (202) and the counterelectrode (203) when the work function of the transparent electrode(202) and the counter electrode (203) is different, electrons passbetween electron acceptors, holes pass between electron donors, andphotocurrents are detected. For example, when the work function of thetransparent electrode (202) is larger than the work function of thecounter electrode (203), electronics are transported to the transparentelectrode (202) and holes are transported to the counter electrode(203). When the magnitude of the work function is reversed, electronsand holes are transported in the opposite direction. In addition, byapplying a potential between the transparent electrode (202) and thecounter electrode (203), the transport direction of electrons and holesmay be controlled.

Although not indicated in FIG. 2, another layer such as a hole blockinglayer, an electron blocking layer, an electron injection layer, a holeinjection layer, or a smoothing layer may be included.

In addition, for the purpose of further improving the solar light useefficiency (photoelectric conversion efficiency), a tandem typestructure (a structure having a plurality of bulk heterojunction layers)in which such photoelectric conversion elements are stacked may be used.

FIG. 3 is a cross-sectional view indicating a solar cell composed of anorganic photoelectric conversion element having a tandem bulkheterojunction layer. In the case of the tandem configuration, atransparent electrode (202) and a first photoelectric conversion portion(209) are sequentially stacked on a substrate (201), a chargerecombination layer (intermediate electrode 205) is then stacked, andthen a second light conversion portion (206) and then a counterelectrode (203) are stacked, whereby a tandem structure may be obtained.

Examples of materials that may be used for the above-described layersinclude n-type semiconductor materials and p-type semiconductormaterials described in paragraphs 0045 to 0113 of JP-A No. 2015-149483.

(Method for Forming Bulk Heterogeneous Junction Layer)

As a method of forming a bulk heterojunction layer in which an electronacceptor and an electron donor are mixed, an evaporation method or acoating method (including a casting method and a spin coating method)may be exemplified. Among them, a coating method is preferable in orderto increase the area of the interface between holes and electronics forcharge separation and to manufacture an element having highphotoelectric conversion efficiency. The coating method is alsoexcellent in production speed.

In the present invention, the n-type semiconductor material and thep-type semiconductor material constituting the bulk heterojunction layermay be used as the organic material for an electronic device of thepresent invention. That is, the bulk heterojunction layer is preferablyformed by coating a solution containing the n-type semiconductormaterial and the p-type semiconductor material, the organic solvent, andthe cellulose nanofiber. In the coating liquid containing the n-typesemiconductor material and the p-type semiconductor material, theorganic solvent, and the cellulose nanofiber, the dissolved carbondioxide concentration in the organic solvent under the atmosphericpressure condition at 50° C. or less is preferably 1 ppm to thesaturation concentration in the organic solvent.

As a means for setting the dissolved carbon dioxide concentration in theabove range, as described above, a method of bubbling carbon dioxide gasinto a solution containing an n-type semiconductor material and a p-typesemiconductor material, an organic solvent, and a cellulose nanofiber,or a supercritical chromatography method using a supercritical fluidcontaining an organic solvent and carbon dioxide may be cited.

After the coating, heating is preferably performed in order to removeresidual solvent, moisture, gas, and cause improvement in mobility andabsorption long wave by crystallization of the semiconductor material.When annealing is performed at a predetermined temperature during themanufacturing process, alignment or crystallization is promoted in aportion in a microscopic manner, so that the bulk heterojunction layermay be formed into a suitable phase separation structure. As a result,the carrier mobility of the bulk heterojunction layer is improved, andhigh efficiency may be obtained.

The photoelectric conversion unit (bulk heterojunction layer) 204 may beformed of a single layer in which an electron acceptor and an electrondonor are uniformly mixed, or may be formed of a plurality of layers inwhich a mixing ratio of the electron acceptor and the electron donor ischanged.

Next, electrodes constituting the organic photoelectric conversionelement will be described.

In the organic photoelectric conversion element, the positive charge andthe negative charge generated in the bulk heterojunction layer are takenout from the transparent electrode and the counter electrode through thep-type organic semiconductor material and the n-type organicsemiconductor material, respectively, and function as a battery. Eachelectrode is required to have characteristics suitable for carrierspassing through the electrode.

(Counter Electrode)

In the present invention, the counter electrode (cathode) is preferablyan electrode from which electrons are extracted. For example, in thecase of use as a cathode, a single layer of a conductive material may beused, but a resin holding these materials may be used in combinationwith a material having conductivity.

The counter electrode material is required to have sufficientconductivity, to have a work function close to that of not forming aSchottky barrier when bonded to the n-type semiconductor material, andnot to deteriorate. That is, metals having a work function of 0 to 0.3eV higher than that of LUMO of n-type semiconducting materials used inthe bulk heterojunction layers are preferable, and 4.0 to 5.1 eV arepreferable. On the other hand, since it is not preferable that the workfunction is deeper than that of the transparent electrode (anode) fromwhich holes are extracted, and interlayer resistance may occur in ametal having a work function shallower than that of the n-typesemiconductor material, it is actually preferable that the metal has awork function of 4.2 to 4.8 eV. Therefore, aluminum, gold, silver,copper, indium, or oxide-based materials such as zinc oxide, ITO, andtitanium oxide are also preferable. Aluminum, silver, copper, and silverare more preferable.

The work function of these metals may also be measured using ultravioletphotoelectron spectroscopy (UPS).

Alloys may be used as required, and for example, magnesium/silvermixtures, magnesium/aluminum mixtures, magnesium/indium mixtures,aluminum/aluminum oxide (Al₂O₃) mixtures, lithium/aluminum mixtures, andaluminum, and are suitable. The counter electrode may be manufactured byforming a thin film of these electrode materials by a method such asevaporation or sputtering. The film thickness is usually selected in therange of 10 nm to 5 μm, preferably 50 to 200 nm.

Further, when the opposite electrode side is made light transmissive,for example, a light transmissive opposite electrode may be obtained bymanufacturing a conductive material suitable for the opposite electrode,such as aluminum and aluminum alloy, silver, or a silver compound, in athin film thickness of about 1 to 20 nm, and then providing a film of aconductive light transmissive material.

(Transparent Electrode)

In the present invention, the transparent electrode is preferably anelectrode from which holes are extracted. For example, when theelectrode is used as an anode, it is preferably an electrode whichtransmits light of 380 to 800 nm. As the material, for example, atransparent conductive metal oxide such as indium-tin oxide (ITO), SnO₂or ZnO, a metal thin film such as gold, silver or platinum, a metalnanowire, or a carbon nanotube may be used.

Further, polypyrrole, polyaniline, polythiophene, polythiophene,polyethylene vinylene, polyazulene, polyisothianaphthene, polycarbazole,polyacetylene, polyphenylene, polyphenylene vinylene, polyacetylene,conductive polymer or the like selected from the group consisting ofeach derivative of polydiacetylene and polynaphthalene may also be used.In addition, a transparent electrode may be formed by combining aplurality of these conductive compounds.

(Intermediate Electrode)

As a material of the intermediate electrode required for the tandemconfiguration, a layer using a compound having both transparency andconductivity is preferable, and a material used for the transparentelectrode (a transparent metal oxide such as ITO, AZO, FTO, titaniumoxide, a very thin metal layer such as Ag, Al, Au, or the like, a layercontaining nanoparticles and nanowires, a conductive polymer materialsuch as PEDOT:PSS, or polyaniline may be used.

Note that the above-mentioned hole transport layer and electrontransport layer may be combined to function as an intermediate electrode(charge recombination layer) by appropriately combining and stackingthem, and in such a configuration, it is possible to omit the step offorming one layer.

Next, the material constituting other than the electrode and the bulkheterojunction layer will be described.

(Hole Transport Layer and Electron Blocking Layer)

Since the organic photoelectric conversion element enables moreefficient extraction of charges generated in the bulk heterojunctionlayer, it is preferable that the bulk heterojunction layer and thetransparent electrode have a hole transport layer and an electronblocking layer between them.

As a material constituting these layers, for example, as the holetransporting layer, PEDOT such as Clevious manufactured by Heraeus Inc.,polyaniline and its doping material, a cyanide compound described inWO2006/019270 may be used.

Note that the hole transporting layer having a LUMO level shallower thanLUMO level of the n-type semiconducting materials used in the bulkheterojunction layer is given an electronic blocking function having arectifying effect such that electrons generated in the bulkheterojunction layer do not flow to the transparent electrodes. Such ahole transport layer is also called an electron blocking layer, and itis preferable to use a hole transport layer having such a function. Assuch a material, it is possible to use a triarylamine-based compounddescribed in JP-A 5-271166, also molybdenum oxide, nickel oxide, a metaloxide such as tungsten oxide. Alternatively, a layer composed of ap-type semiconductor material alone used for the bulk heterojunctionlayer may be used. The means for forming these layers may be either avacuum deposition method or a solution coating method, but it ispreferably a solution coating method. It is preferable to form thecoating film on the lower layer before forming the bulk heterojunctionlayer because it has the effect of leveling the coating surface andreduces the influence of leakage.

(Electron Transport Layer, Hole Blocking Layer, and Buffer Layer)

The organic photoelectric conversion element preferably has an electrontransport layer, a hole blocking layer, and a buffer layer formedbetween the bulk heterojunction layer and the counter electrode, so thatcharges generated in the bulk heterojunction layer may be extracted moreefficiently.

As the electron transport layer, octaazaporphyrin or a perfluorocompound of a p-type semiconductor (perfluoropentacene orperfluorophthalocyanine) may be used, but similarly, the electrontransport layer having a HOMO level deeper than HOMO level of the p-typesemiconductor material used for the bulk heterojunction layer isprovided with a hole blocking function having a rectifying effect suchthat holes generated in the bulk heterojunction layer do not flow to theopposite electrode side. Such an electron transport layer is also calleda hole blocking layer, and it is preferable to use an electron transportlayer having such a function. As such a material, a phenanthrene-basedcompound such as vasocuproine, an n-type semiconductor material such asnaphthalenetetracarboxylic anhydride, naphthalenetetracarboxylic aciddiimide, perylenetetracarboxylic anhydride, or perylenetetracarboxylicacid diimide, an n-type inorganic oxide such as titanium oxide, zincoxide, or gallium oxide, or a layer composed of a simple n-typesemiconductor material used for a bulk heterojunction layer may be used.

Alternatively, an alkali metal compound such as lithium fluoride, sodiumfluoride, or cesium fluoride may be used.

Among these, it is preferable to use an alkali metal compound whichfurther has a function of doping an organic semiconductor molecule andimproving electrical bonding with the metal electrode. In the case of analkali metal compound layer, it may be referred to as a buffer layer inparticular.

(Other Layer)

In order to improve the energy conversion efficiency and the devicelifetime, various intermediate layers may be provided in the device.Examples of the intermediate layer include a hole blocking layer, anelectron blocking layer, a hole injection layer, an electron injectionlayer, an exciton blocking layer, a UV absorbing layer, a lightreflecting layer, and a wavelength conversion layer.

(Substrate)

When light to be photoelectrically converted is incident from thesubstrate side, it is preferable that the substrate be a member capableof transmitting the light to be photoelectrically converted, that is,transparent to the wavelength of the light to be photoelectricallyconverted. As the substrate, for example, a glass substrate or a resinsubstrate is suitably given, but it is desirable to use a transparentresin film from the viewpoint of lightness and flexibility.

There is no particular limitation on the transparent resin film which ispreferably used as a transparent substrate in the present invention, andthe material, shape, structure, and thickness thereof may beappropriately selected from known ones. For example, a resin film havinga transmittance of 80 nm or more at a wavelength of 800 nm isparticularly preferable as long as it is a polyester resin film such aspolyethylene terephthalate (PET), polyethylene naphthalate (PEN), ormodified polyester, a polyethylene (PE) resin film, a polypropylene (PP)resin film, a polystyrene resin film, a polyolefin resin film such as acyclic olefin resin film, a vinyl resin film such as polyvinyl chlorideor polyvinylidene chloride, a vinyl resin film such as polyphenyleneether ketone (PEEK) resin film, a polysulfone (PSF) resin film, apolyether sulfone (PES) resin film, a polycarbonate (PC) resin film, apolyamide resin film, a polyimide resin film, an acrylic resin film, ora triacetyl cellulose resin film. Among them, from the viewpoints oftransparency, heat resistance, ease of handling, strength and cost,biaxially oriented polyethylene terephthalate film, biaxially orientedpolyethylene naphthalate film, polyether sulfone film and polycarbonatefilm are preferable, and biaxially oriented polyethylene terephthalatefilm and biaxially oriented polyethylene naphthalate film are morepreferable.

The transparent substrate used in the present invention may be providedwith a surface treatment or an easy adhesive layer in order to securewettability and adhesiveness of the coating liquid. Conventional knowntechniques may be used for the surface treatment and the easy adhesivelayer. For example, the surface treatment may include surface activationtreatment such as corona discharge treatment, flame treatment,ultraviolet treatment, high-frequency treatment, glow dischargetreatment, active plasma treatment, and laser treatment. Examples of theeasy adhesive layer include layers made of polyester, polyamide,polyurethane, vinyl copolymer, butadiene copolymer, acrylic copolymer,vinylidene copolymer, and epoxy copolymer.

In addition, for the purpose of suppressing the transmission of oxygenand water vapor, a barrier coat layer may be formed in advance on thetransparent substrate.

(Optical Function Layer)

The organic photoelectric conversion element may have various opticalfunctional layers for the purpose of more efficient reception ofsunlight. As the optical function layer, for example, the followinglayers may be provided: an anti-reflection film, a light collectinglayer such as a microlens array, and a light diffusion layer so thatlight reflected at the counter electrode may be scattered and madeincident on the bulk heterojunction layer again.

As the anti-reflection layer, various known anti-reflection layers maybe provided, and for example, when the transparent resin film is abiaxially oriented polyethylene terephthalate film, it is morepreferable to set the refractive index of the easy adhesive layeradjacent to the film to 1.57 to 1.63 because the interface reflectionbetween the film substrate and the easy adhesive layer may be reducedand the transmittance may be improved. As a method of adjusting therefractive index, coating may be performed by appropriately adjustingthe ratio of an oxide sol having a relatively high refractive index,such as a tin oxide sol or a cerium oxide sol, to a binder resin. Theeasy adhesive layer may be a single layer, but may be formed of two ormore layers in order to improve the adhesiveness.

As the light collecting layer, for example, by processing to provide astructure on the microlens array on the sunlight receiving side of thesupport substrate, or by combining with a so-called light collectingsheet, it is possible to increase the amount of light received from aspecific direction, and conversely, to reduce the incident angledependence of sunlight.

As an example of the microlens array, a quadrangular pyramid having aside of 30 μm and a vertex angle of 90 degrees is two-dimensionallyarranged on the light extraction side of the substrate. One side lengthis preferably in the range of 10 to 100 μm. When it is smaller than thisvalue, the diffraction effect is generated and colored, and when it isexcessively large, the thickness becomes thick, which is not preferable.

Examples of the light scattering layer include various anti-glarelayers, and a layer in which nanoparticles or nanowires of metals orvarious inorganic oxides are dispersed in a colorless and transparentpolymer.

(Patterning)

The method or process of patterning the electrode, the power generationlayer, the hole transport layer, and the electron transport layer is notparticularly limited, and a known method may be appropriately applied.

When the material is a soluble material such as a bulk heterojunctionlayer or a transport layer, unnecessary portions may be wiped off aftercoating the entire surface with a die coating or dip coat coating, ormay be directly patterned at the time of coating using a method such asan inkjet printing method or a screen printing method.

In the case of insoluble materials such as electrode materials, theelectrodes may be mask deposited during vacuum deposition or patternedby known methods such as etching or lift-off. Alternatively, the patternmay be formed by transferring a pattern formed on another substrate.

(Sealing)

In addition, in order to prevent the manufactured organic photoelectricconversion element from being deteriorated by oxygen and moisture in theenvironment, it is preferable that sealing is performed by a knownmethod for an organic photoelectric conversion element or an organic ELelement other than the organic thin film and the organic laminated filmof the present invention. For example, a method of sealing a cap made ofaluminum or glass by adhering it with an adhesive, a method of adheringa plastic film on which a gas barrier layer such as aluminum, siliconoxide, or aluminum oxide is formed and an organic photoelectricconversion element with an adhesive, a method of spin coating an organicpolymer material having a high gas barrier property (polyvinyl alcoholor the like), a method of depositing an inorganic thin film having ahigh gas barrier property (silicon oxide, aluminum oxide, or the like)or an organic film (e.g., parylene) under vacuum, and a method ofstacking these may be mentioned.

[4.3] Organic Thin Film Transistor

FIG. 4 is a schematic cross-sectional view indicating the structure ofthe organic thin film transistor. In the drawing, the organic thin filmor the organic multilayer film of the present invention is omitted, butthe entire device is covered with the organic thin film or the organicmultilayer film similarly to the organic EL element described above.

FIG. 4A indicates that a source electrode (302) and a drain electrode(303) are formed on a support (306) using a metal foil, and acharge-transporting thin film (organic semiconductor layer 301) composedof 6,13-bistriisopropylsilylethynylpentacene is formed between bothelectrodes as an organic semiconductor material described in JP-A No.2009-101852, an insulating layer (305) is formed thereon, and a gateelectrode (304) is further formed thereon to form a field effecttransistor.

FIG. 4B indicates an organic semiconductor layer (301), which is formedbetween the electrodes in FIG. 4A, which is formed so as to cover theentire electrode and the support surface using a coating method.

FIG. 4C indicates a structure in which an organic semiconductor layer(301) is first formed on a support (306) by a coating method, and then asource electrode (302), a drain electrode (303), an insulating layer(305), and a gate electrode (304) are formed on the organicsemiconductor layer (301).

In FIG. 4D, after forming the gate electrode (304) on the support (306)with a metal foil, an insulating layer (305) is formed thereon to form asource electrode (302) and a drain electrode (303) with a metal foil,thus, the organic semiconductor layer (301) is formed by a luminescentcomposition of the present invention between the electrodes.

In addition, a configuration as indicated in FIG. 4E and FIG. 4F may beadopted.

EXAMPLES

Hereinafter, the present invention will be described in detail withreference to examples, but the present invention is not limited thereto.In the examples, “parts” or ‘%’ is used, but unless otherwise specified,it indicates “parts by mass” or “% by mass”.

Example 1 (Preparation of Organic EL Element)

A glass substrate on which a 100 nm-thick film of ITO (Indium Tin Oxide)was formed as an anode was subjected to ultrasonic cleaning withisopropyl alcohol, dried with dry nitrogen gas and UV-ozone cleaning,and fixed to a substrate holder of a vacuum evaporation device.

Then, HAT-CN (1,4,5,8,9,12-hexaazatriphenylene hexacarbonitrile) wasevaporated to a thickness of 10 nm to provide hole injection-transportlayer.

Next, a-NPD (4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl) wasvapor-deposited on the hole injection layer to provide a hole transportlayer having a thickness of 40 nm.

Then, mCP (1,3-bis(N-carbazolyl)benzene) as a host material andbis[2-(4,6-difluorophenyl)pyridinato-C2,N)(picolinato)iridium(III)(FIrpic)as a light-emitting compound were co-evaporated to be 94% and 6% byvolume, respectively, to provide a 30 nm-thick light-emitting layer.

Thereafter, BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) wasvapor-deposited to provide an electron transport layer with a thicknessof 330 nm.

Further, 100 nm-thick silver was further vapor-deposited to provide acathode.

(Preparation of Sealing Film 1)

A solution of titanium tetraisopropoxide (Ti(OiPr)₄) in 3% by mass indehydrated tetrafluoropropanol (exemplified compound F-1) was preparedin a glove box under a dry nitrogen atmosphere having a water content of1 ppm or less, and the solution was opened to the atmosphere having ahumidity of 30% for 1 minute, and immediately returned to the inside ofthe glove box as a sol-gel solution.

An organic multilayer film composed of a sol-gel solution and an elutionpreventing film was coated and formed on the cathode of the organic ELelement under the conditions indicated in Table I below.

The organic multilayer film refers to a multilayer film in which acoating solution containing polydimethylsiloxane (PDMS) is first coatedand deposited on the negative electrode to a thickness of 250 nm, UVirradiation is performed for one minute, and then VUV irradiation isperformed for one minute, and then the sol-gel solution is furthercoated on a film containing PDMS to a thickness of 100 nm, and a film isformed by UV, VUV, or heat, and organic thin films are stacked.

Next, the following gas barrier film was produced as a sealing member ofthe entire organic EL element.

An inorganic gas barrier layer made of SiO_(x) was formed on the entiresurface of a polyethylene naphthalate film (manufactured by Teijin FilmSolution Co., Ltd.) to a thickness of 500 nm by using an atmosphericpressure plasma-discharge treatment device having a configurationdescribed in JP-A No. 2004-68143. Thus, a flexible gas barrier filmhaving a gas barrier property with an oxygen permeability of 0.001mL/(m²·24 h·atm) or less and a water vapor permeability of 0.001g/(m²·24 h) or less was produced. On one surface of the gas barrierfilm, a thermosetting liquid adhesive (epoxy resin) was formed to athickness of 25 μm as a sealing resin layer. Then, the gas barrier filmprovided with the sealing resin layer was superimposed on the elementformed by coating the sol-gel solution. At this time, the surface of thegas barrier film on which the sealing resin layer was formed wascontinuously superimposed on the sealing surface side of the organic ELelement so that the ends of the extraction portions of the anode and thecathode were exposed to the outside.

Next, the sample to which the gas barrier film was attached was placedin a decompression device, and held for 5 minutes by pressing under adecompression condition of 0.01 MPa at 90° C. The sample was thenreturned to atmospheric pressure and heated at 90° C. for 30 minutes tocure the adhesive.

The above sealing step was performed under atmospheric pressure, under anitrogen atmosphere having a moisture content of 1 ppm or less, inaccordance with JIS B 9920, at a Class 100 cleanliness, a dew pointtemperature of −80° C. or less, and an atmospheric pressure at an oxygenconcentration of 0.8 ppm or less. The sealing film 1 in which theorganic EL element was sealed was manufactured by the above method. Across-sectional view of the organic EL element is indicated in FIG. 1.

(Preparation of Sealing Films 2 to 26)

The sealing films 2 to 26 were produced in the same manner as thesealing film 1 except that the presence or absence of the elutionpreventing film, the type of raw material of the sol-gel solution, thefilm forming conditions, and the organic EL element configuration werechanged as indicated in Table I. Cross-sectional views of the organic ELelement are shown in FIGS. 1, and 5 to 9.

The compound of the comparative example used in the sealing film 25 wasa compound having a structure represented by the chemical formula (1)described in JP-A No. 2005-000792, and a compound having the followingstructure was used.

(Comparative Compound)

Heating was performed using a hot plate in a glove box. TheUV-irradiation was performed by irradiating a low-pressure mercury lampin a glove box at an intensity of 37 mW/cm². The VUV-irradiation wasperformed by irradiating xenon excimer light in a glove box at anintensity of 65 mW/cm².

<Evaluation>

The luminescence state after leaving at 60° C. and 90% RH for one weekwas observed, and the sealing performance was evaluated. Specifically, a100-fold optical microscope (MS-804 manufactured by Moritex Corporation,a lens MP-ZE25-200) was photographed by enlarging a portion of thelight-emitting portion of the organic EL element. Next, the photographedimage was cut out in 2 mm squares, and the presence or absence of darkspot generation was observed for each image. The ratio of the area ofdark spots generated to the area of light emission was determined fromthe observation results, and the dark spot resistance was evaluatedaccording to the following criteria.

5: There is no occurrence of dark spots.

4: The area of dark spot generation is 0.1% or more and less than 1.0%.

3: The area of dark spot generation is 1.0% or more and less than 3.0%.

2: The area of dark spot generation is 3.0% or more and less than 6.0%.

1: The area of dark spot generation is 6.0% or more.

The composition and evaluation results of the sealing film are indicatedin Table I below.

TABLE I Organic thin film Elution (Sealing film: Sol-gel liquidcomposition) Cross-sectional preventing Film forming view of OrganicDark spot Sealing film No. film Metal alkoxide Alcohol condition ELelement resistance Remarks Sealing film 1 Present Ti(OiPr)₄ F-1 *1 FIG.1 4 Present invention Sealing film 2 Present Ti(OiPr)₄ F-1 UVirradiation FIG. 1 4 Present invention for 30 minutes Sealing film 3Present Ti(OiPr)₄ F-1 Heating at 100° FIG. 1 3 Present invention C. for30 minutes Sealing film 4 Present Ti(OiPr)₄ F-1 *1 Ti(OiPr)₄ F-1 3 timescoating FIG. 1 5 Present invention of sol-gel liquid Sealing film 5Present Ti(OiPr)₄ F-2 *1 FIG. 1 4 Present invention Sealing film 6Present Ti(OiPr)₄ F-5 *1 FIG. 1 4 Present invention Sealing film 7Present Ti(OiPr)₄ F-6 *1 FIG. 1 3 Present invention Sealing film 8Present Ti(OiPr)₄ F-3 *1 FIG. 1 4 Present invention Sealing film 9Present Ti(OiPr)₄ F-4 *1 FIG. 1 4 Present invention Sealing film 10Present Ti(OiPr)₄ F-7 *1 FIG. 1 3 Present invention Sealing film 11Present Ti(OiPr)₄ F-8 *1 FIG. 1 3 Present invention Sealing film 12Present Ti(OiPr)₄ F-9 *1 FIG. 1 4 Present invention Sealing film 13Present Ti(OiPr)₄ F-10 *1 FIG. 1 4 Present invention Sealing film 14Present Ti(OiPr)₄ F-11 *1 FIG. 1 4 Present invention Sealing film 15Present Ti(OiPr)₄ F-12 *1 FIG. 1 3 Present invention Sealing film 16Present Ti(OiPr)₄ F-13 *1 FIG. 1 4 Present invention Sealing film 17Present Ti(OiPr)₄ F-14 *1 FIG. 1 4 Present invention Sealing film 18Present Ti(OiPr)₄ F-15 *1 FIG. 1 3 Present invention Sealing film 19Present Ti(OiPr)₄ F-16 *1 FIG. 1 4 Present invention Sealing film 20Absent Ti(OiPr)₄ F-1 *1 FIG. 7 3 Present invention Sealing film 21 Onlygas barrier film is used FIG. 5 1 Comparative example Sealing film 22Present Absent FIG. 6 1 Comparative example Sealing film 23 PresentTi(OiPr)₄ 2-Methoxyethanol *1 FIG. 8 2 Comparative example Sealing film24 Present Ti(OiPr)₄ N-butanol *1 FIG. 8 2 Comparative example Sealingfilm 25 Present Desiccant having a chemical structure — FIG. 8 2Comparative example (Chem. 1) in JP-A 2005-000792 Sealing film 26Present CaO — FIG. 9 2 Comparative example *1: VUV irradiation for 1minute

From the above evaluation results, it was confirmed that high sealingperformance was obtained by the sealing film formed by coating accordingto the present invention.

Example 2

Using the same configuration as that of the sealing film 1 of Example 1,the metal alkoxide raw material used for the sealing film was changed asindicated in Table II to prepare sealing films 2-1 to 2-8, and thesealing performance (dark spot resistance) was evaluated.

In the sealing films 2-5 and 2-6, two metal alkoxides were mixed at amolar ratio of 50:50.

For the comparative sealing films 2-7 and 2-8, isopropanol (IPA) wasused as alcohol.

In doing so, dark spot resistance was evaluated according to thefollowing criteria.

6: There is no occurrence of dark spots.

5: Dark spot generation area is 0.1% or more and less than 0.5%.

4: The area of dark spot generation is 0.5% or more and less than 1.0%.

3: The area of dark spot generation is 1.0% or more and less than 3.0%.

2: The area of dark spot generation is 3.0% or more and less than 6.0%.

1: The area of dark spot generation is 6.0% or more.

The composition and evaluation results of the sealing film are indicatedin Table II.

TABLE II Organic thin film Elution (Sealing film: Sol-gel liquidcomposition) Cross-sectional preventing Film forming view of OrganicDark spot Sealing film No. film Metal alkoxide Alcohol condition ELelement resistance Remarks Sealing film 2-1 Present Ti(OiPr)₄ F-1 VUVirradiation FIG. 1 3 Present invention for 1 minute Sealing film 2-2Present Mg(OiPr)₂ F-1 VUV irradiation FIG. 1 4 Present invention for 1minute Sealing film 2-3 Present Ba(OiPr)₂ F-1 VUV irradiation FIG. 1 4Present invention for 1 minute Sealing film 2-4 Present Sr(OiPr)₂ F-1VUV irradiation FIG. 1 5 Present invention for 1 minute Sealing film 2-5Present Si(OiPr)₄—Ti(OiPr)₄ F-1 VUV irradiation FIG. 1 3 Presentinvention for 1 minute Sealing film 2-6 Present Sr(OiPr)₂—Ti(OiPr)₄ F-1VUV irradiation FIG. 1 6 Present invention for 1 minute Sealing film 2-7Present Ti(OiPr)₄ IPA VUV irradiation FIG. 1 1 Comparative example for 1minute Sealing film 2-8 Present Sr(OiPr)₂ IPA VUV irradiation FIG. 1 1Comparative example for 1 minute

From the above evaluation results, it was confirmed that even when themetal alkoxide raw material according to the present invention waschanged, high sealing performance was obtained in the same manner as inExample 1. Among them, it has been found that it is more preferable touse Sr of the second group element.

Example 3

The sol-gel solution used in Example 1 was applied onto a silicon waferwith a thickness of 100 nm, and a thin film was produced under the samefilm forming conditions as in Example 1. The prepared thin film wasanalyzed by the above-mentioned SEM/EDS (Energy Dispersive X-raySpectoroscopy: energy-dispersive X-ray analyzer) to obtain the values ofthe following Expression (a). SEM/EDS equipment was made by JSM-IT100(JEOL Ltd).

Elemental analysis by SEM/EDS (energy dispersive X-ray spectrometer) andthe values obtained by the following Expression (a) are indicated inTable III.

F/(C+F)   Expression (a):

(In Expression (a), F and C represent the concentrations of fluorine andcarbon atoms, respectively.)

TABLE III Sol-gel liquid composition Metal alkoxide Alcohol F/(C + F)Ti(OiPr)₄ F-1 0.20 Ti(OiPr)₄ F-2 0.33 Ti(OiPr)₄ F-5 0.42 Ti(OiPr)₄ F-60.19

According to the results of Table III, the thin film prepared from thesol-gel solution of Example 1 contains some fluorine atoms. It wasrecognized that it was fastened in the film by the combination.

Example 4

Next, in Example 4, the sealing property of a lighting device (and anelement) emitting blue fluorescence, which was manufactured by theinkjet printing method, was confirmed.

<Preparation of Lighting Device for Evaluation> (Preparation ofSubstrate)

First, on the entire surface of a polyethylene naphthalate film(manufactured by Teijin Film Solution Co., Ltd.) on which an anode wasformed, an inorganic gas barrier layer made of SiO_(x) was formed to athickness of 500 nm by using an atmospheric pressure plasma-dischargetreatment device having a structure described in JP-A No. 2004-68143.Thus, a flexible base material having a gas barrier property with anoxygen permeability of 0.001 mL/(m²·24 h·atm) or less and a water vaporpermeability of 0.001 g/(m²·24 h) or less was produced.

(Formation of Anode)

An ITO (indium tin oxide) film having a thickness of 120 nm was formedon the above-mentioned base material by a sputtering method, and waspatterned by a photolithography method to form an anode. The pattern wassuch that the area of the light-emitting region was 5 cm×5cm.

(Formation of Hole Injection Layer)

The substrate on which the anode was formed was ultrasonically cleanedwith isopropyl alcohol, dried with dry nitrogen gas, and subjected to UVozone cleaning for 5 minutes. Then, on the substrate on which the anodewas formed, a 2% by mass solution obtained by diluting apoly(3,4-ethylenedioxythiophene)/polystyrene sulfonate (PEDOT/PSS)dispersion prepared in the same manner as in Example 16 of JapanesePatent No. 4509787 was applied by an inkjet printing method, and driedat 80° C. for 5 minutes to form a hole injecting layer having a layerthickness of 40 nm.

(Formation of Hole Transport Layer)

Next, the base material on which the hole injection layer was formed wastransferred to a nitrogen atmosphere using a nitrogen gas (grade G1),applied by an inkjet printing method using a coating solution forforming a hole transport layer having the following composition, anddried at 150° C. for 30 minutes to form a hole transport layer having alayer thickness of 30 nm.

<Coating Solution for Forming Hole Transport layer>

Hole transport material HT-3 (weight-average molecular weight Mw=80000):10 parts by mass

(p)-Xylene: 3000 parts by mass

(Formation of Light-Emitting Layer)

Next, the base material on which the hole transport layer was formed wascoated by an inkjet method using a coating solution for forming alight-emitting layer having the following composition, and dried at 130°C. for 30 minutes to form a light-emitting layer having a layerthickness of 50 nm.

<Coating Solution for Forming Light-Emitting Layer>

Host compound H-4: 9 parts by mass

Metal complex CD-2: 1 part by mass

Fluorescent materials F-1: 0.1 parts by mass

Normal butyl acetate: 2,000 parts by mass

(Formation of Blocking Layer)

Next, the base material on which the light-emitting layer was formed wascoated by an inkjet method using a coating solution for forming ablocking layer having the following composition, and dried at 80° C. for30 minutes to form a blocking layer having a layer thickness of 10 nm.

<Coating Solution for Forming Blocking Layer>

HB-4: 2 parts by mass

Isopropyl alcohol (IPA): 1500 parts by mass

2,2,3,3,4,4,5,5-Octafluoro-1-pentanol: 500 parts by mass

(Formation of Electron Transport Layer)

Next, the base material on which the blocking layer was formed wascoated by an inkjet printing method using a coating solution for formingan electron transport layer having the following composition, and driedat 80° C. for 30 minutes to form an electron transport layer having alayer thickness of 30 mm.

<Coating Solution for Forming Electron Transport Layer>

ET-1: 6 parts by mass

2,2,3,3-tetrafluoro-1-propanol: 2000 parts by mass

(Formation of Electron Injection Layer and Cathode)

The substrate was then attached to a vacuum deposition apparatus withoutexposure to the atmosphere. A resistance heating boat made of molybdenumcontaining sodium fluoride and potassium fluoride was attached to avacuum evaporation apparatus, and the vacuum chamber was depressurizedto 4×10⁻⁵ Pa. Thereafter, the boat was energized and heated to depositsodium fluoride at 0.02 nm/sec on the electron transport layer to form athin film having a thickness of 1 mm. Similarly, potassium fluoride wasvapor-deposited on the sodium fluoride thin film at 0.02 nm/sec to forman electron injection layer having a thickness of 1.5 nm.

Subsequently, aluminum was vapor-deposited to form a cathode having athickness of 100 nm.

Thereafter, in the same manner as in Example 1, a sealing film using anelution preventing film and a sol-gel liquid (conditions used for thesealing film 1) was produced on the cathode by an inkjet printingmethod, and thereafter, the gas barrier film described in Example 1 wasbonded to produce an organic EL element using an inkjet printing method.The compounds used are indicated below.

<Evaluation>

The organic EL element having the sealing film 1 was improved in darkspot resistance in a state of being left at 60° C. and 90% RH for oneweek in the same manner as in Example 1, as compared with the organic ELelement having no sealing film formed by the sol-gel solution (thesealing film 21 and the sealing film 22 in Example 1). From the above,it was confirmed that, even in the lighting device manufactured by theinkjet printing method, a high sealing performance is obtained by thesealing film formed by coating and deposition according to the presentinvention.

Example 5

A sol-gel solution of Example 1 (conditions used for the sealing film 1)was applied and deposited on a silicon wafer, and the contact angle ofpure water before and after the obtained organic thin film being left tostand at 60° C. and 90% RH for 1 hour was measured by the followingsolution method. As a result, the contact angle with pure water was 40°before leaving, whereas after leaving, the contact angle increased to60°. From the above results, it was recognized that the organic thinfilm prepared from the sol-gel liquid released a hydrophobic(water-repellent) substance when it came into contact with moisture, andthe hydrophobicity (water repellency) of the surface was enhanced by theorientation of the film on the film surface.

<Measurement of Contact Angle>

The contact angle of pure water on the surface of the organic thin filmswas measured by dropping 1 μL of pure water to the samples of theorganic thin films before and after being left at 60° C. and 90% RH for1 hour on the basis of JIS-R3257 in an atmosphere of 23° C. and 55% RHusing a contact angle meter (manufactured by Kyowa Interface ScientificCo., Ltd., product name DropMaster DM100), and measuring the contactangle after 1 minute. In the measurement, 10 points were measured atequal intervals in the width direction of the organic thin film, and theaverage value was set as the contact angle except for the maximum valueand the minimum value.

Example 6

An organic thin film solar cell (organic photoelectric conversionelement) was manufactured by using a sealing film formed by coating ofthe present invention.

<Preparation of Organic Photoelectric Conversion Element>

A glass substrate on which a 100 nm-thick film of ITO (Indium Tin Oxide)was formed as an anode was subjected to ultrasonic cleaning withisopropyl alcohol, dried with dry nitrogen gas and UV-ozone cleaning,and fixed to a substrate holder of a vacuum evaporation device.

After the degree of vacuum in the vacuum evaporation device was reducedto 1×10⁻⁴ Pa, copper phthalocyanine (CuPC) and anthra[9,1,2-c,d,e:10,5,6-c′,d′,e′][bis[benzimidazolo[2,1-a]isoquinoline]]-10,21-dione(PTCBI) were co-evaporated at a ratio of CuCP:PTCBI=1:1 on the anode,and a bulk heterojunction layer was formed at a thickness of 400 nm.

Subsequently, aluminum (100 nm) was deposited as a cathode.

Subsequently, an elution preventing film and a sealing film wereproduced in this order on the cathode under the conditions of thesealing film 1 of Example 1 to produce an organic photoelectricconversion element.

<Evaluation>

When the obtained organic photoelectric conversion element wasirradiated with light having a strength of 100 mW/m² of a solarsimulator in a state of being left at 60° C. and 90% RH for 10 days, theorganic photoelectric conversion element on which the sealing film 1 wasapplied maintained a photocurrent in an initialization state as comparedwith the organic photoelectric conversion element on which the sol-gelliquid was not formed (the sealing film 21 and the sealing film 22 ofExample 1). From the above results, it was also confirmed that in theorganic photoelectric conversion element, high sealing performance wasobtained by the sealing film formed by coating of the present invention.

Example 7

An organic thin film transistor was manufactured by using a sealing filmformed by coating of the present invention.

<Preparation of Organic Thin Film Transistor>

In accordance with FIG. 4A, a source electrode (302) and a drainelectrode (303) were formed on a support (306) using a metal foil. Then,an organic semiconductor layer having a thickness of about 30 nm as acharge transfer thin film (organic semiconductor layer 301) composed of6,13-bistriisopropylsilylethynylpentacene as an organic semiconductormaterial described in JP-A No. 2009-101852 between the both electrodes.Then, an insulating layer (305) was formed thereon, and a gate electrode(304) was further formed thereon, thereby manufacturing an organic thinfilm transistor.

Subsequently, an elution preventing film and a sealing film were formedin this order on the insulating layer (305) and the gate electrode (304)under the conditions of the sealing film 1 of Example 1, therebyfabricating an organic thin film transistor.

<Evaluation>

The obtained organic thin film transistor was left at 60° C. and 90% RHfor 10 days, and the operation characteristics of the p-channelenhancement FET (Field-Effect Transistor) were evaluated, and theorganic thin film transistor provided with the sealing film 1 exhibitedbetter operation characteristics and carrier transfer characteristicsthan the organic thin film transistor (the sealing film 21 and thesealing film 22 of Example 1) in which the sol-gel liquid was notformed. From the above results, it was confirmed that the sealing filmformed by coating of the present invention provides high sealingperformance also in the organic thin film transistor.

Example 8

The water absorption property of the sol-gel liquid according to thepresent invention was measured based on the following method.

<Preparation of Organometallic Oxides>

A solution of various metal alkoxides (M(OR)_(x)) indicated in Table IVin 3 mass % dehydrated tetrafluoropropanol (exemplified compound F-1)was prepared in a glove box under a dry nitrogen atmosphere having amoisture concentration of 1 ppm or less. After bubbling 40 mL of airhaving a humidity of 50%, the solution immediately returned into theglove box was used as a sol-gel solution. The two metal alkoxides weremixed at a molar ratio of 50:50 at the level of two metal alkoxides.

<Evaluation> (Evaluation of Water Absorption Amount)

The water absorption was evaluated by the following method.

Since fluoride alcohols (R′—OD), which are water-repellent orhydrophobic substances, are formed by reacting heavy water (D₂O) withmetallic alkoxides, the water absorption was measured by detectingR′—OD. In other words, R′—OD was detected after leaving in a D₂Oatmosphere for 3 hours. A temperature-rising desorption analyzer TDS1200(manufactured by Electronics Sciences Co., Ltd.) was used for thedetection.

The results are indicated in Table IV.

The amount of water absorbed was judged on the basis of the number ofmoles of R′—OD of metal alkoxide detected.

BB: 1≤R′—OD≤2

AA: 2≤R′—OD

TABLE IV VUV Reforming Sol-gel liquid treatment Water compositioncondition absorption Metal alkoxide Alcohol (J/cm²) amount Ti(OiPr)₄ F-12 BB Mg(OiPr)₂ F-1 2 BB Sr(OiPr)₂ F-1 2 AA Ba(OiPr)₂ F-1 2 BBSr(OiPr)₂—Ti(OiPr)₄ F-1 2 AA

From the results of Table IV, the sol-gel solution of the presentinvention was excellent in water absorption because it had a large waterabsorption amount, and among these, the level using Sr of the Group 2element was further excellent in water absorption.

INDUSTRIAL APPLICABILITY

The desiccant of the present invention can be used for sealing moisturepermeation to an electronic device such as an organic electroluminescentdevice, and the organic thin film containing the same and the organiclaminated film in which the organic thin film is laminated are suitablyused for an electronic device such as an organic electroluminescentdevice, a photoelectric conversion device, an organic thin film solarcell, and an organic thin film transistor.

DESCRIPTION OF SYMBOLS

-   10: Element-   100: Organic EL element-   101: Substrate-   102: Glass cover or gas barrier film-   103: Adhesive-   105: Cathode-   106: Organic functional layer-   107: Glass substrate with transparent electrode-   108: Organic thin film (sealing film)-   109: Other organic thin film (elution preventing film)-   110: Organic thin film outside the present invention-   111: Watering material-   200: Bulk heterojunction type organic photoelectric conversion    device-   201: Substrate-   202: Transparent electrode (anode)-   203: Counter electrode (cathode)-   204: Photoelectric conversion unit (bulk heterojunction layer)-   205: Charge recombination layer-   206: Second photoelectric conversion unit-   207: Hole transport layer-   208: Electron transport layer-   209: First photoelectric conversion unit-   301: Semiconductor layer-   302: Source electrode-   303: Drain electrode-   304: Gate electrode-   305: Insulating layer-   306: Support

1. A desiccant comprising a compound which releases a hydrophobicsubstance upon absorption of water.
 2. An organic thin film containingthe desiccant described in claim
 1. 3. The organic thin film describedin claim 2, wherein the desiccant contains an organometallic oxide. 4.The organic thin film described in claim 3, wherein the organometallicoxide has a structure represented by the following Formula (1),R-[M(OR1)y(O—)x-y]n-R   Formula (1): wherein, R represents hydrogenatoms, an alkyl group having or more carbon atoms, an alkenyl group, anaryl group, a cycloalkyl group, an acyl group, an alkoxy group, or aheterocyclic group, provided that R may be a carbon chain containing afluorine atom as a substituent, M represents a metal atom, OR1represents a fluorinated alkoxy group, x represents a metal valence, yrepresents any integer between 1 and x, and n represents a degree ofpolycondensation, respectively.
 5. The organic thin film described inclaim 2, wherein the fluorine ratio of the organic thin film satisfiesthe following Expression (a),0.05≤F/(C+F)≤1,   Expression (a): wherein, F and C represent densitiesof fluorine and carbon atoms, respectively.
 6. The organic thin filmdescribed in claim 4, wherein the metal atom represented by M is a Group2 element.
 7. The organic thin film described in claim 6, wherein themetal atom represented by M is strontium.
 8. The organic thin filmdescribed in claim 4, wherein the organic thin film contains at leasttwo kinds of organometallic oxides having a structure represented byFormula (1), and wherein at least one kind of metal atom is a Group 2element.
 9. An organic laminated film in which the organic thin filmdescribed in claim 2 and another organic thin film are laminatedadjacently.
 10. An electronic device comprising: at least an organicfunctional layer; and an organic thin film described in claim 2 or anorganic multilayer film described in claim 9 above the organicfunctional layer.
 11. The electronic device described in claim 10,wherein the organic thin film is an elution preventing film and isdisposed between the organic functional layer and the organic thin film.12. The electronic device described in claim 10, wherein the electronicdevice is an organicelectroluminescent element.